Systems, structures and materials for electrochemical device thermal management

ABSTRACT

A casing for the thermal management and protection of an electrochemical cell, the casing comprises a first material, an inner surface configured to be in physical contact with an electrochemical cell, wherein the inner surface is substantially solid at room temperature; and a polymer matrix dispersed within the first material and comprising two or more temperature management materials. At least one of the two or more temperature management materials comprise a phase change material having a latent heat of at least 5 Joules per gram and a transition temperature between 0° C. and 100° C., and an elastomeric material. The polymer matrix is substantially homogeneous, and in an environment where the electrochemical cell and a second electrochemical cell operate under the same charging and discharging conditions, the casing reduces a first operating temperature of the electrochemical cell by at least 10° C.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/014,624 filed Feb. 3, 2016 and titled “SYSTEMS, STRUCTURES ANDMATERIALS FOR ELECTROCHEMICAL DEVICE THERMAL MANAGEMENT,” pending, whichis a continuation-in-part of U.S. patent application Ser. No. 14/614,223filed Feb. 4, 2015, titled “SYSTEMS, STRUCTURES AND MATERIALS FORELECTROCHEMICAL DEVICE THERMAL MANAGEMENT,” and issued as U.S. Pat. No.10,003,053 on Jun. 19, 2018, the entire disclosures of which are herebyincorporated by reference for all proper purposes, as if fully set forthherein.

FIELD OF THE DISCLOSURE

In general, the present disclosure relates to systems, structures andcompositions used to enhance the performance and safety ofelectrochemical devices by managing their thermal properties.

BACKGROUND OF THE DISCLOSURE

Demand continues to grow for electrochemical devices, such as batteriesand capacitors, that can power portable electronics, power tools,components of vehicles, and entire vehicles themselves. Many modernbattery and electric double layer capacitor systems (EDLCS), in whichmultiple battery or capacitor cells can be packed near each other, havehigh power and energy density requirements for operation. As an example,Lithium-ion (Li ion), Li ion polymer, and Li ion liquid batteries havebecome the popular choice for a wide range of applications, especiallyin portable electronics and electric vehicles because of their energydensity, high voltage, and negligible memory effects. However, largerpower demands and increasing cell density of Li ion battery packs resultin higher operating temperatures, especially under peak loads. Li ionbatteries, as well as most other types of commercial electrochemicalcell chemistries, are susceptible to degrading or aging at hightemperatures, which leads to rapid loss of capacity over subsequentcharge/discharge cycles as well as reduced overall power output.

It is well known that the heat given off by batteries during charge anddischarge has detrimental effects on the performance and longevity ofthe batteries. It is known that this heat can create safety hazards aswell. Similar concerns exist regarding other kinds of electrochemicalcells. Regarding battery performance and longevity, an increase inoperational heat can reduce such performance and longevity even if theheat is not severe enough to create a safety hazard. For example, anincrease in just 10 to 20 degrees Celsius can result in a drasticreduction in battery life. External heat conditions can degrade abattery, but in addition, the repeated charge and discharge of a batteryitself in operation can cause drastic thermal escalation. In the priorart, there currently exist a number of insulators that attempt tomitigate large temperature escalation during charge and discharge,thereby relieving performance degradation over life of the battery andincreasing the safety of the battery system. There are also existingbattery cell covers and sleeves that have mechanical properties thatprotect cells from external damage. The existing covers, sleeves, andinsulators have varying degrees of effectiveness.

Existing commercial battery cells and packs utilize various passive andactive cooling systems in order to manage temperature fluctuationsgenerated by both ambient conditions and cell operation. Both active andpassive thermal management systems rely on thermal transfer of heat awayfrom the cell's surface, thereby inhibiting core temperature rise andlimiting material degradation. The effectiveness of regulating coretemperatures is both a function of the ability to efficiently transferheat away from the cell surface and the inherent thermal properties ofthe battery materials. Active cooling methods include forced airconvection, fluidized cooling, and heat pipes, which rely on pumps,fans, radiators, and connections to function. The equipment required forthese systems can be bulky, heavy, and expensive. While active coolingmethods are effective in shuttling heat away from a surface, especiallyduring significant thermal generation, their size and complexity areprohibitive in many applications, such as in portable electronics andtools.

Regarding the safety hazards associated with battery heat, it is wellknown that overheated cells can cause fires and explosions, andsubsequently produce toxic products and gases, especially if certaincells or their components come in direct contact with each other.Battery safety has become increasingly important as the number ofconsumer devices that rely on batteries has increased. Consumersincreasingly come in physical contact with batteries in their phones,laptops, and other portable devices. Additionally, many vehiclecomponents and entire vehicles are now powered by batteries, and thesafety requirements of batteries in those applications are especiallyhigh. For example, battery packs used to power components of airplanesmust be extremely fire resistant, due to the danger associated withfires on airplanes. As another example, electric vehicles powered bybattery packs have the risk of damage to the battery packs due toimpacts from collisions. One problem is that overheating can cause aphenomenon known as thermal runaway, wherein the overheating of one cellcan cause other nearby cells to overheat, and the combined effectexponentially increases the temperature of many cells at once, which canlead to fires or explosions. To simply prevent cells from physicallycontacting each other, sleeves made of various materials, such as PVCand cardboard have been used, though many such materials have little tono heat-resistant effects. There exists a need for electrochemical cellcasings or sleeves that offer improved protection and thermal managementover the prior art.

SUMMARY OF THE DISCLOSURE

Exemplary embodiments are summarized below. These and other embodimentsare more fully described in the Detailed Description section. It is tobe understood, however, that there is no intention to limit thedisclosure to the forms described in this Summary of the Disclosure orin the Detailed Description. One skilled in the art can recognize thatthere are numerous modifications, equivalents and alternativeconstructions that fall within the spirit and scope of the disclosure asexpressed in the claims.

One aspect of the disclosure provides a casing for the thermalmanagement and protection of an electrochemical cell pack. The casingmay comprise a first material and an inner surface configured to be inphysical contact with at least a portion of an outer surface of anelectrochemical cell, wherein the inner surface is substantially solidat room temperature. The casing may further comprise a polymer matrixdispersed within the first material and comprising two or moretemperature management materials. At least one of the two or moretemperature management materials may comprise a phase change materialhaving a latent heat of at least 5 Joules per gram and a transitiontemperature between 0° C. and 100° C., and at least one other of the twoor more temperature management materials may comprise an elastomericmaterial. The polymer matrix may be substantially homogeneous, and, inan environment where the electrochemical cell and a secondelectrochemical cell operate under the same charging and dischargingconditions, the casing may reduce a first operating temperature of theelectrochemical cell by at least 10° C. compared to a second operatingtemperature of the second electrochemical cell encased by a secondcasing comprising the first material and not the polymer matrix.

Another aspect of the disclosure provides a container for the thermalmanagement and protection of an electrochemical cell. The container maycomprise a first material and a polymer matrix dispersed within thefirst material and comprising two or more temperature managementmaterials. At least one of the two or more temperature managementmaterials may comprise a phase change material having a latent heat ofat least 5 Joules per gram and a transition temperature between 0° C.and 100° C., and at least one other of the two or more temperaturemanagement materials may comprise an elastomeric material. The polymermatrix may be substantially homogeneous, and, in an environment wherethe electrochemical cell pack and a second electrochemical cell packoperate under the same charging and discharging conditions, thecontainer may reduce a first operating temperature of at least oneelectrochemical cell in the electrochemical cell pack by at least 10° C.compared to a second operating temperature of at least oneelectrochemical cell of the second electrochemical cell pack encased bya second container comprising the first material and not the polymermatrix.

Many additional aspects and embodiments are described herein as would berecognized by one of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects and advantages and a more complete understanding of thepresent disclosure are apparent and more readily appreciated byreference to the following Detailed Description and to the appendedclaims, when taken in conjunction with the accompanying Drawingswherein:

FIG. 1A shows a diagram of a single cylindrical battery cell;

FIG. 1B shows a diagram of a single prismatic battery cell;

FIG. 1C shows a diagram of a single cylindrical capacitor cell;

FIG. 1D shows a diagram of a single prismatic capacitor cell;

FIG. 1E shows a high level diagram of a cylindrical battery cell and itsinternal protection components;

FIGS. 2A-2D show prior art battery packs in casings;

FIG. 3 shows a high level view of an elastomer;

FIG. 4A shows an empty cylindrical casing and cells in cylindricalcasings in accordance with an embodiment of the present disclosure;

FIG. 4B shows an empty rectangular casing, and rectangular or prismaticcells in rectangular casings in accordance with an embodiment of thepresent disclosure.

FIG. 4C shows various embodiments of casings that can hold multipleelectrochemical cells in accordance with the present disclosure.

FIG. 4D shows additional rectangular embodiments of casings that canretain multiple electrochemical cells in accordance with the presentdisclosure.

FIG. 5A shows a top view of a sleeve embodiment of the casingsurrounding a battery cell;

FIG. 5B shows a top view of a tape embodiment of the casing surroundinga battery cell;

FIGS. 6A-6C show embodiments of thermal management material inaccordance with some embodiments of the present disclosure;

FIGS. 7-10D show various embodiments of functional polymeric phasechange materials;

FIG. 11 shows one embodiment of the precisely branched polymers comparedwith randomly distributed polymers;

FIG. 12 is a graph depicting the peak melting point of variouscopolymers;

FIG. 13 is a graph depicting the heat of crystallization of variouscopolymers;

FIG. 14 is a graph depicting the latent heat and melting point ofvarious copolymers;

FIGS. 15A and 15B show details of a microcapsule as used in connectionwith various aspects of the present disclosure;

FIGS. 16A-16C show various layering embodiments that may be used inconnection with aspects of the present disclosure;

FIG. 17 is a graph that illustrates the degradation of capacity inbattery cells over time;

FIG. 18 is a graph illustrating how an embodiment of the disclosurereduced operating temperatures of cells being discharged;

FIG. 19 is a graph illustrating the surface temperatures of cells in anexperiment testing an embodiment of the disclosure;

FIG. 20 is a graph illustrating the discharge capacity retention ofcells in the experiment illustrated in FIG. 19;

FIG. 21 is a diagram of an experiment to test performancecharacteristics of electrochemical cells when charged and dischargedwithin a temperature management casing of the present disclosure.

FIG. 22 is a graph showing the temperatures of the cells of FIG. 21during the experiment.

FIG. 23 is another graph showing the temperatures of the cells of FIG.21 during the experiment.

FIG. 24 shows graphs illustrating the temperatures at various locationsin casings with different thermal conductivity properties.

FIG. 25 a graph showing the discharge retention capacity of a cell in acasing according to an embodiment of the present disclosure compared tothat of a control cell with no casing.

Other embodiments and aspects are disclosed herein, including variousfigures and process descriptions described and illustrated throughoutthe specification.

DETAILED DESCRIPTION

Throughout this specification, references are made to the use of variousmaterials, combinations, chemical formulations and other aspects thatmay be used in various combinations to form one or more materials, endproducts, or compositions in accordance with aspects of the presentdisclosure. It should be understood, both to one of skill in the art aswell as the examining divisions in the United States Patent Office andPatent Offices throughout the world, that each of the lists ofmaterials, examples, and other embodiments are included herein in orderto teach one of skill in the art that they may be combined into variousalternative embodiments, without requiring specific claim permutationsof these individual features. The claims as presented herein, as well asany potential future amendments to those claims, may include one or morecombinations of these materials, ranges and other alternatives withoutdeparting from the spirit and scope of the disclosure described herein.In particular it is contemplated that one of skill in the art wouldrecognize and find adequate support in the written description for anycombination of the features disclosed herein, whether described in asingle example or embodiment, or described in different sections of thewritten description. The description of these various examples andoptions is specifically drafted to comply with 35 U.S.C. § 112 of theUnited States Patent Laws, Article 123(2) of the European Patent Laws aswell as other similar national country laws relating to the adequacy ofthe written description.

It should be clearly understood that by providing examples of specificcompositions and methods in the later part of this description,applicant does not intend to limit the scope of the claims to any ofthose specific compositions. To the contrary, it is anticipated that anycombination of the functional groups, phase change materials, andarticles described herein may be utilized to achieve the novel aspectsof the present disclosure. The claims are not intended to be limited toany of the specific compounds described in this disclosure or anydisclosure incorporated herein.

The present disclosure provides various descriptions of materials,apparatuses, devices, systems, methods, and methods of manufacturingrelating to the thermal management of electrochemical cells.Electrochemical cells are a broad category, well-known types of whichinclude batteries and capacitors. The terms “electrochemical cell,”“battery,” “capacitor,” and their plurals and variants may be usedinterchangeably throughout the disclosure. The term “cell” is often usedto refer to a single enclosed electrochemical cell containing, but notlimited to, electrodes, such as an anode and cathode, and electrolyte,and used to denote a device that can generate electrical energy from oneor multiple chemical interactions or facilitate one or multiple chemicalinteractions from electrical energy. Numerous types of batteries areknown, and certain popular commercially-available batteries will bedepicted for the purposes of illustration and reference throughout thisdisclosure. Numerous types of capacitors are known, and certain popularcommercially available capacitors, such as electric double-layercapacitors, or supercapacitors, will also be depicted throughout thisdisclosure. The term “pack” (often, “battery pack”) is also often usedto refer to a group of enclosed cells which have terminals that arelinked together. For the purposes of this disclosure, the term “cell”will be used to refer to a single electrochemical cell (e.g., a batteryor capacitor cell), and the term “pack” will be used to refer to anarrangement of multiple cells that have connected terminals. The term“electrochemical devices” will be used to refer more broadly to one ormore electrochemical cells, which may or may not be arranged in a pack.Though many examples throughout this disclosure may refer to batterycells specifically in certain applications, it is to be understood thatthose examples are not limiting, and may be applicable to other types ofelectrochemical cells as well without departing from the scope of thisdisclosure. Examples of specific configurations of cells and packs withwhich aspects of the present disclosure may be utilized will bediscussed later in this disclosure.

One problem with existing materials for managing the thermal propertiesof electrochemical devices is that they are not necessarily constructedfor impact resistance. Another problem with existing materials is thatthey are not designed to fit electrochemical devices tightly. The latterproblem is due in part to the fact that electrochemical devices come inmultiple sizes and shapes, and even within a given configuration thereis considerable size variation. For instance, 18650 lithium-ion cellsare widely available and come in a size that is nominally 18.6 mm indiameter×65.2 mm in length, but the diameter can vary by 0.5-1 mmdepending on the manufacturer. Such size variation can create problems;if any air gaps exist between the surface of the cell and the sleeve,the air gaps act as insulators, and can actually increase thetemperature of the cell, as will be discussed in greater detailthroughout this disclosure.

Passive systems of cooling typically refer to the use of materials totransfer heat away from heat sources. In contrast with earlier-describedactive systems, passive systems are typically simple in design andeliminate the need for mechanical equipment and additional capacity topower them. One effective kind of passive system for managing heatdissipation involves the use of latent heat storage materials, oftenknown as phase change materials. However, application of phase changematerials in commercial cells and battery packs has been minimal due todeficiencies in the presently available material properties. Thesedeficiencies lead to poor thermal transfer/storage and rigid applicationrequirements. The use of phase change materials (PCMs) in variousindustries to store and release heat is known. PCMs are latent heatstorage materials that absorb and store thermal heat during a change inmaterial phase. The use of various forms and compositions of PCMs(micro-encapsulated or raw), their methods of manufacture andapplications thereof have been widely disclosed in fields such astextiles and fabrics, building insulation, and electronics. For example,see U.S. Pat. No. 8,587,945, “Systems Structures and Materials forElectronic Device Cooling,” incorporated herein by reference in itsentirety. Further, the use of PCMs to manage the thermal properties ofbatteries are known. For example, see U.S. Pat. No. 7,270,910, “ThermalManagement Systems for Battery Packs,” which discloses PCMs dispersedwithin a gel for cooling batteries. Also, see U.S. Pat. No. 6,942,944,“Battery System Thermal Management,” which discloses filling spaceswithin battery packs entirely with PCMs. However, the systems,compositions, or methods previously disclosed do not adequately addressthe problems of varying battery sizes, air gaps, the need for varyingsizes of the materials themselves, ease of use and transport,waterproofing, corrosion resistance, fire resistance, and impactresistance. Further, the thermal management performance of the existingcompositions themselves can be improved. Therefore, there exists a needto remedy these deficiencies.

It is known that good thermal management materials should have highthermal conductivity, high specific heat capacity, high latent heatcapacity, high polytropic heat capacity, low coefficient of thermalexpansion, low air content, good gap-filling, good surface wetting andadhesion, and good rheology.

One aspect of the present disclosure is that one or more PCMs can bedispersed within a matrix of another temperature management material(TMM) and formed as a tight casing or sleeve around an individualelectrochemical cell. Throughout the disclosure, a TMM casing thatcontains one or more dispersed PCMs may be referred to as a PCM-TMMcasing or sleeve, or alternatively as a TMM-PCM casing or sleeve. Insome embodiments, the terms PCM-TMM or TMM-PCM may refer to casings orsleeves that are mostly comprised of PCMs, with very little non-PCM TMM,or vice versa. In some embodiments, wherein the electrochemical cell iscylindrical, the sleeve may be open at both ends to allow the exposureof the cell's positive and negative terminals. In other embodiments, forexample, wherein the electrochemical cell is prismatic or pouch-shapedand both terminals are located at one end, the sleeve or other casingmay be closed at one end.

Another aspect of the present disclosure is that the sleeve or casingmay be solid at room temperature and at substantially all temperatureranges of normal electrochemical device operation (excluding, forexample, prolonged exposure to fire). A benefit of forming a tightsleeve of made of one or more PCMs dispersed within a TMM matrix that issolid is that the sleeve may be easily transported and applied toindividual cells. Known properties of solid TMMs with dispersed PCMsinclude that they are non-corrosive, non-toxic, and chemically inert,making them easy to handle. As a result, there is greater flexibilityregarding when and where a sleeve may be applied within themanufacturing process of an electrochemical cell or of an end productcontaining an electrochemical device. For example. A battery cellmanufacturer itself could apply the sleeve, or the end productmanufacturer could apply the sleeve. End users who own electrochemicaldevices could even apply the sleeve on used electrochemical devices toprolong the devices' capacities and lives.

Another aspect of the present disclosure is that a solid sleeve may beformed as an individual-cell-sized unit or as a sleeve pre-formed to fita configuration of a particular electrochemical device. Examples of suchconfigurations will be discussed in greater detail throughout thisdisclosure. A benefit to an individual-cell-sized sleeve is that it canbe removed and replaced if it is damaged by heat or impact, even ifother cells or sleeves in a pack are not damaged. An individually-sizedsleeve can also be implemented by a wide range of users and industries,because the number of sleeves required can be scaled up and down. Forthese benefits, individual-cell-sized sleeves made of materials such asplastic, PVC, or metal have been used in the prior art. However, PCMshave not been used in the solid sleeve configuration. PCM-filled gelshave also been used in the prior art. This solid sleeve provides anadvantage over using a PCM-filled gel to provide thermal managementwithin a battery pack, for example, as discussed in U.S. Pat. No.7,270,910, previously referenced in this disclosure. A PCM gel can bedifficult to transport and apply, and may be limited to applicationwithin certain steps in the manufacturing process. A gel wouldnecessarily need to be enclosed within a container surrounding anelectrochemical cell or pack, and such a container would likely need tobe specifically manufactured for a particular configuration of anelectrochemical device.

Similarly, an individual-cell-sized sleeve can have advantages oversimply filling the interstitial air spaces between within the cells ofan electrochemical pack with PCM that is sometimes solid and sometimesliquid, as described in U.S. Pat. No. 6,942,944, referenced earlier inthis disclosure. For example, filling interstitial spaces in anelectrochemical pack likely requires using injection or pouring in themanufacturing process, which would limit the application to certainsteps in the manufacturing process. Such application of PCM is not asversatile or scalable as an individual solid sleeve.

A pre-formed integral set of sleeves configured for specificelectrochemical packs could also provide advantages. For example, a setof individual sleeves can be attached to each other during manufacturingso as to allow multiple cells to share the same structural material. Anintegral set of sleeves may comprise 8 sleeves in a row, or 64 sleevesin a block, as just two non-limiting examples. It may be beneficial tomanufacture sleeves in these configurations for particular commercialapplications, such as standard battery pack sizes used in a particularkind of consumer electronic device.

Another aspect of the disclosure is that the solid sleeve may haveelastomeric properties. That is, the matrix TMM itself and/or the PCMitself may stretch in order to ensure close contact with individualbattery cells, even if a “standard” sized commercial battery cell has aslight variance in size from other standard cells. In addition, theseelastomeric properties can include thermal elasticity and rebound, ormemory. That is, as the heat of the electrochemical cell itself changesand causes physical expansion and contraction of the cell, the sleevecan expand and contract with it in order to keep close contact. Thereare several advantages to of this kind of elastomeric property. Oneadvantage is the reduction of air gaps between the sleeve and the cellsurface, which can be accomplished due to the elastomeric properties bymaintaining very close contact. Reducing air gaps is an advantagebecause air is a poor conductor of heat away from a heat source. If airis trapped between a battery cell and any surrounding material, the airgap can act as insulation and actually cause an electrochemical cell toget hotter than it would if there were no surrounding material.Currently, plastic, PVC, and metal sleeves are used to protect andinsulate electrochemical devices. Not only are these materials inferiorto PCMs in terms of heat dissipating properties, but they additionallydo not have elastomeric properties that minimize the effect of air gaps.As these materials expand and contract and lose contact with the cellsurface, air gaps can actually increase, and the heat surrounding thecell can increase, thereby further contributing to the degradation ofthe cell and the sleeve over time.

Yet another aspect of the disclosure is that TMMs and or PCMs comprisinggels or greases may be used in conjunction with the solid sleeve inorder to facilitate the application of the sleeve and to increase thecontact between the sleeve and the cell. Because the gels and greasesare in a liquid state, they may expand and contract and flow to areasbetween the cell and the sleeve that may have tiny gaps. The combinationof the elastomeric sleeve and the gels or greases further diminishes thepresence of air gaps. Another benefit of the tight fit accomplished bythe elastomeric properties and/or gels and greases is that the contactbetween the outside of a cell and the TMM can provide homogeneity in theoverall temperature of the cell. That is, some cells can normallygenerate hot spots, meaning one part of the cell is much hotter thananother. Such hot spots can lead to cell degradation. The PCM-TMM sleevein close contact can dissipate the heat generated by a hot spot to thePCM-TMM directly in contact with the hot spot and transfer it to PCM-TMMthat is not directly in contact with the hot spot. As a result, thetemperature of and around the entire cell can remain substantiallyhomogeneous.

Another aspect of the disclosure is that a PCM-TMM casing can keep cellswarm in extreme cold weather environments. It is known that extreme coldcan cause battery cells to discharge more quickly and to lose capacitybecause the internal chemistry of the cell is disrupted. Because PCMsare latent-heat storage materials, they can insulate articles from theloss of heat and increase the temperature that would be necessary toproduce detrimental effects. In some embodiments, layers of PCMs thatprovide protection from extreme cold can be combined with layers thatdissipate excess heat. Various ranges of PCM properties necessary forinsulating electrochemical devices from extreme cold will be describedthroughout the disclosure. Alternatively, a TMM casing may primarilycontain a PCM for the purposes of absorbing excess heat, but may alsoinclude one-way insulation such as a reflective layer or reflectiveinsulation for protection from excess cold.

Yet another aspect of the disclosure is that the sleeve or casing mayhave corrosion resistant, waterproof, fire-retardant or impact-resistantproperties. These aspects may comprise additives to the PCM, the TMM, orboth. The advantages of such properties in applications for batterycells and battery packs will be discussed in further detail in thisdisclosure.

Another aspect of the disclosure provides a sleeve or casing comprisinga particular kind of PCM-TMM that comprises a crosslinked polyetherpolyol in a uniform, substantially homogenous composition throughout theentirety of the sleeve or casing structure. These crosslinked polyetherpolyols may comprise polyethylene glycols (PEG) or polyethylene oxides(PEO) to form shape-stable, moldable, and machinable casings with latentheat storage properties and fire resistant properties. Various chainextenders may be reacted with the polyether polyols in order to achievethe crosslinking, which allows for adjustment of the chain length, andtherefore the mol. wt. of the polyether polyols. Numerous embodimentsand the advantages thereof will be described in further detail in thisdisclosure.

Many aspects of the disclosure relate to thermal conductivity. Thermalconductivity, or the rate of heat transfer across a material andexpressed as watts per meter kelvin (W/(m·K)) or W·m⁻¹·K⁻¹, iscontrolled by the flow of free electrons or crystal lattice vibrations(phonons). In metals, conductivity is primarily due to free electrons,whereas for nonmetals it is mainly due to phonon transport. Thermalconductivity can vary dependent on type of materials, temperature,material phase, impurities, etc. For instance, the change in thermalconductivity that occurs when ice (thermal conductivity of 2.18 W/(m·K)at 0° C.) melts into liquid water (thermal conductivity of 0.58 W/(m·K)at 0° C.). Another example is for pure crystalline substances canexhibit different thermal conductivities along different crystal axes,due to differences in phonon coupling along a given crystal axis. Thethermal conductivity of plastics depends strongly on the degree ofcrystallinity in polymers (Anisotropicity of crystalline polymers). Thisis mostly due to phonon transport (flowing lattice vibrational energy)that is efficient along the crystalline axis but reduced substantiallyin amorphous areas or by various scattering processes in the otherdirections.

Definitions

The following definitions apply to various elements described withrespect to various aspects of the disclosure. These definitions maylikewise be expanded upon herein.

As used herein, the term “monodisperse” refers to being substantiallyuniform with respect to a set of properties. Thus, for example, a set ofmicrocapsules that are monodisperse can refer to such microcapsules thathave a narrow distribution of sizes around a mode of the distribution ofsizes, such as a mean of the distribution of sizes. A further example isa set of polymer molecules with similar molecular weights.

As used herein, the term “latent heat” refers to an amount of heatabsorbed or released by a material as it undergoes a transition betweentwo states. Thus, for example, a latent heat can refer to an amount ofheat that is absorbed or released as a material undergoes a transitionbetween a liquid state and a crystalline solid state, a liquid state anda gaseous state, a crystalline solid state and a gaseous state, twocrystalline solid states or crystalline state and amorphous state or anycombination thereof.

As used herein, the term “transition temperature” refers to anapproximate temperature at which a material undergoes a transitionbetween two states. Thus, for example, a transition temperature canrefer to a temperature at which a material undergoes a transitionbetween a liquid state and a crystalline solid state, a liquid state anda gaseous state, a crystalline solid state and a gaseous state, twocrystalline solid states or crystalline state and amorphous state. Atemperature at which an amorphous material undergoes a transitionbetween a glassy state and a rubbery state may also be referred to as a“glass transition temperature” of the material or combination thereof.

As used herein, the term “phase change material” refers to a materialthat has the capability of absorbing or releasing heat to adjust heattransfer at or within a temperature stabilizing range. A temperaturestabilizing range can include a specific transition temperature or arange of transition temperatures. This allows for the adjustment of heattransfer or thermal conductivity within this transition range. In someinstances, a phase change material can be capable of inhibiting heattransfer during a period of time when the phase change material isabsorbing or releasing heat, typically as the phase change materialundergoes a transition between two states. This action is typicallytransient and will occur until a latent heat of the phase changematerial is absorbed or released during a heating or cooling process.Heat can be stored or removed from a phase change material, and thephase change material typically can be effectively “recharged” by asource that emits or absorbs heat. For certain implementations, a phasechange material can be a mixture of two or more materials. By selectingtwo or more different materials and forming a mixture, a temperaturestabilizing range can be adjusted for any desired application. Theresulting mixture can exhibit two or more different transitiontemperatures or a single modified transition temperature whenincorporated in the articles described herein.

As used herein, the term “polymer” refers to a material that includes aset of macromolecules. Macromolecules included in a polymer can be thesame or can differ from one another in some fashion. A macromolecule canhave any of a variety of skeletal structures, and can include one ormore types of monomeric units. In particular, a macromolecule can have askeletal structure that is linear or non-linear. Examples of non-linearskeletal structures include branched skeletal structures, such as thosethat are star branched, comb branched, or dendritic branched, andnetwork skeletal structures. A macromolecule included in a homopolymertypically includes one type of monomeric unit, while a macromoleculeincluded in a copolymer typically includes two or more types ofmonomeric units. Examples of copolymers include statistical copolymers,random copolymers, alternating copolymers, periodic copolymers, blockcopolymers, radial copolymers, and graft copolymers. In some instances,a reactivity and a functionality of a polymer can be altered by additionof a set of functional groups, such as acid anhydride groups, aminogroups and their salts, N-substituted amino groups, amide groups,carbonyl groups, carboxy groups and their salts, cyclohexyl epoxygroups, epoxy groups, glycidyl groups, hydroxy groups, isocyanategroups, urea groups, aldehyde groups, ester groups, ether groups,alkenyl groups, alkynyl groups, thiol groups, disulfide groups, silyl orsilane groups, groups based on glyoxals, groups based on aziridines,groups based on active methylene compounds or other b-dicarbonylcompounds (e.g., 2,4-pentandione, malonic acid, acetylacetone,ethylacetone acetate, malonamide, acetoacetamide and its methylanalogues, ethyl acetoacetate, and isopropyl acetoacetate), halo groups,hydrides, or other polar or H bonding groups and combinations thereof.Such functional groups can be added at various places along the polymer,such as randomly or regularly dispersed along the polymer, at ends ofthe polymer, on the side, end or any position on the crystallizable sidechains, attached as separate dangling side groups of the polymer, orattached directly to a backbone of the polymer. Also, a polymer can becapable of cross-linking, entanglement, network formation, ionicbonding, covalent bonding or hydrogen bonding in order to increase itsmechanical strength or its resistance to degradation under ambient orprocessing conditions. As can be appreciated, a polymer can be providedin a variety of forms having different molecular weights, since amolecular weight of the polymer can be dependent upon processingconditions used for forming the polymer. Accordingly, a polymer can bereferred to as having a specific molecular weight or a range ofmolecular weights. As used herein with reference to a polymer, the term“molecular weight” can refer to a number average molecular weight, aweight average molecular weight, or a melt index of the polymer.

Examples of polymers (including those polymers used for crosslinkers andbinders) include polyhydroxyalkonates, polyamides, polyamines,polyimides, polyacrylics (e.g., polyacrylamide, polyacrylonitrile, andesters of methacrylic acid and acrylic acid), polycarbonates (e.g.,polybisphenol A carbonate and polypropylene carbonate), polydienes(e.g., polybutadiene, polyisoprene, and polynorbornene), polyepoxides(e.g. bisphenol A, bisphenol F, multifunctional glycidyl based epoxieseither cross-linked or uncrosslinked with amines, acids, alcohols,etc.), polyesters (e.g., polycaprolactone, polyethylene adipate,polybutylene adipate, polypropylene succinate, polyesters based onterephthalic acid, and polyesters based on phthalic acid), polyethers(e.g., polyethylene glycol or polyethylene oxide, polybutylene glycol,polypropylene oxide, polyoxymethylene or paraformaldehyde,polytetramethylene ether or polytetrahydrofuran, andpolyepichlorohydrin), polyfluorocarbons, formaldehyde polymers (e.g.,urea-formaldehyde, melamine-formaldehyde, and phenol formaldehyde, canbe in their monomeric or polymeric forms, can have some degree ofhydroxyl methylation, etherification, and/or alkylation), naturalpolymers (e.g., polysaccharides, such as cellulose, chitan, chitosan,and starch; lignins; proteins; and waxes), polyolefins (e.g.,polyethylene, polypropylene, polybutylene, polybutene, and polyoctene),polyphenylenes, silicon-containing polymers (e.g., polydimethylsiloxane, polyalkyl siloxanes and polycarbomethyl silane),polyurethanes, polyvinyls (e.g., polyvinyl butyral, polyvinyl alcohol,esters and ethers of polyvinyl alcohol, polyvinyl acetate, polystyrene,polymethylstyrene, polyvinyl chloride, polyvinyl pryrrolidone,polymethyl vinyl ether, polyethyl vinyl ether, and polyvinyl methylketone), polyacetals, polyarylates, alkyd-based polymers (e.g., polymersbased on glyceride oil), copolymers (e.g., polyethylene-co-vinyl acetateand polyethylene-co-acrylic acid, styrene-butadiene, or any combinationof the above), and mixtures thereof. The term polymer is meant to beconstrued to include any substances that become available after thefiling of this application and that exhibit the general polymericproperties described above.

As used herein, the term “chemical bond” and its grammatical variationsrefer to a coupling of two or more atoms based on an attractiveinteraction, such that those atoms can form a stable structure. Examplesof chemical bonds include covalent bonds and ionic bonds. Other examplesof chemical bonds include hydrogen bonds and attractive interactionsbetween carboxy groups and amine groups.

As used herein, the term “covalent bond” means a form of chemicalbonding that is characterized by the sharing of pairs of electronsbetween atoms, or between atoms and other covalent bonds.Attraction-to-repulsion stability that forms between atoms when theyshare electrons is known as covalent bonding. Covalent bonding includesmany kinds of interactions, including σ-bonding, π-bonding, metal-metalbonding, agostic interactions, and three-center two-electron bonds.

As used herein, the term “ionic bond” or “electrovalent bond” means abond formed through electrostatic attraction between oppositely chargedions. For example, between a positively charged cation and a negativelycharged anion. Ionic bonds can be formed between a metal such as Na, Fe,Ag, etc. and a nonmetal, or between two metals, or between twonon-metals such as ammonia and acids. Ionic compounds can conductelectricity when molten, in a solid or in solution.

As used herein, the term “molecular group” and obvious variationsthereof, refers to a set of atoms that form a portion of a molecule. Insome instances, a group can include two or more atoms that arechemically bonded to one another to form a portion of a molecule. Agroup can be neutral on the one hand or charged on the other, e.g.,monovalent or polyvalent (e.g., bivalent) to allow chemical bonding to aset of additional groups of a molecule. For example, a monovalent groupcan be envisioned as a molecule with a set of hydride groups removed toallow chemical bonding to another group of a molecule. A group can beneutral, positively charged, or negatively charged. For example, apositively charged group can be envisioned as a neutral group with oneor more protons (i.e., H+) added, and a negatively charged group can beenvisioned as a neutral group with one or more protons removed. A groupthat exhibits a characteristic reactivity or other set of properties canbe referred to as a functional group, reactive function or reactivefunctional groups. Examples of reactive functional groups include thosesuch as acid anhydride groups, amino groups, N-substituted amino groupsand their salts, amide groups, carbonyl groups, carboxy groups and theirsalts, cyclohexyl epoxy groups, epoxy groups, glycidyl groups, hydroxygroups, isocyanate groups, urea groups, aldehyde groups, ester groups,ether groups, alkenyl groups, alkynyl groups, thiol groups, disulfidegroups, silyl or silane groups, groups based on glyoxals, groups basedon aziridines, groups based on active methylene compounds or otherb-dicarbonyl compounds (e.g., 2,4-pentandione, malonic acid,acetylacetone, ethylacetone acetate, malonamide, acetoacetamide and itsmethyl analogues, ethyl acetoacetate, and isopropyl acetoacetate), halogroups, hydrides, or other polar or H bonding groups and combinationsthereof.

As used herein the term “Melt flow index” or MFI is a measure of theease of flow of the melt of a polymer. In academic terms the melt flowis defined as the mass of polymer, in grams, flowing in ten minutesthrough a capillary of a specific diameter and length by a pressureapplied via prescribed alternative gravimetric weights for alternativeprescribed temperatures. The method is described in the similarstandards ASTM D1238 and ISO 1133.

As used herein, “Molecular Weight Polydispersity” (a polydispersityindex (PDI)), is a measure of the distribution of molecular mass in agiven polymer sample. The PDI calculated is the weight average molecularweight divided by the number average molecular weight. It indicates thedistribution of individual molecular masses in a batch of polymers. ThePDI has a value equal to or greater than 1, but as the polymer chainsapproach uniform chain length, the PDI approaches unity (1). For somenatural polymers PDI is almost taken as unity. The PDI frompolymerization is often denoted as:

PDI=M _(w) /M _(n)

Mn is more sensitive to molecules of low molecular mass, while Mw ismore sensitive to molecules of high molecular mass. A polymer materialis denoted by the term polydisperse if its chain lengths vary over awide range of molecular masses.

As used herein, “Stereochemistry” means the study of the relativespatial arrangement of atoms within molecules. One branch ofstereochemistry is the study of chiral molecules. Stereochemistry isalso known as 3D chemistry. Examples, explanations, descriptions anddefinitions of various stereochemical nomenclature and naming regimescan be found in Chapter 6 “Stereochemistry” in “Modern Physical OrganicChemistry” by Anslyn and Dougherty, ©2005, University Science Books.

Polymer stereochemistry descriptions of atactic, syndiotactic,isotactic, cis- and trans-, R- and S-, L-, D- and Meso- will be used.

As used herein, “Polymerization” is a process of reacting monomermolecules together in a chemical reaction to form three-dimensionalnetworks or polymer chains. Many forms of polymerization and differentsystems exist to categorize them are known in the art.

As used herein, “Rheology” is the characterization of the flow of matterwhile “viscosity” is the measure of resistance to flow or deformation.Viscosity can be measured by various means and characterized as a meltflow index (MFI) or centipoise (cps), usually at a given temperature orshear rate.

As used herein, the term “thermal conductivity” (“k” and also denoted asλ or κ), is the property of a material's ability to conduct heat and ismeasured in W/m·K. Thermal conductivity is defined as the quantity ofheat (Q) transmitted through a unit thickness (L) in a direction normalto a surface of unit area (A) due to a unit temperature gradient (ΔT)under steady state conditions and when the heat transfer is dependentonly on the temperature gradient. In equation form this becomes thefollowing:

Thermal Conductivity=heat×distance/(area×temperature gradient)

λ=Q×L/(A×ΔT)

Generally, in low conducting materials k<0.1 W/m·K. In good conductingmaterials k=0.1-10 W/m·K. In highly conducting materials k>10 W/m·K. Inaccordance with aspects of the present disclosure, the thermalmanagement and heat dissipation material preferably has a k valueof >0.5 W/m·K. In another embodiment k>1.0 W/m·K and it yet anotherembodiment k is >10 W/m·K.

As used herein, the term “heat dissipation” refers to the movement orspreading of heat from a high temperature environment to a lowtemperature environment, e.g. moving heat from a warm battery to coolerambient air. Methods to dissipate heat can be accomplished by using highthermal conductivity materials such as metallic or ceramic heatspreaders, heat spreader plates, heat sinks, heat pipes, heatexchangers, loop pipes, liquid cold pipes, heat fins, fans, circulatingcoolants or a combination thereof. Further examples are products such asthose supplied by Thermo Cool Corp., Thermacore Inc., etc.

General Composition of Electrochemical Devices

Aspects of the disclosure described herein may be used in connectionwith a wide variety of electrochemical cells and packs that generateheat to the detriment of the performance of the electrochemical cellsand packs themselves. While reference is made herein to such common,commercially available cells such as the lithium-ion 18650 type andother cylindrical batteries, the same features may be incorporated intovirtually any electrochemical cells or packs that require, or couldbenefit from, thermal management during operation. Lithium-ion cellsconfigured in the prismatic format (e.g., the square or rectangular typethat power mobile communication devices) or pouch format (e.g., thosewithout metal outer cans for certain electronic devices) are examples ofshapes that can utilize aspects of the present disclosure. Additionally,electrochemical cells classified as batteries of lithium-based andnon-lithium-based compositions, such as lithium-ion polymer, lithiummetal, solid-state lithium-ion, nickel-based cells includingnickel-cadmium (NiCd), nickel-metal-hydride (NiMH), nickel-iron (NiFE),Nickel-zinc (NiZn), lead acid, zinc-air molten-salt batteries includingsodium-sulfur, sodium-nickel chloride (Na—NiCl2), and magnesium-antimony(MgSB), may also utilize aspects of the present disclosure. Furthermore,electrochemical devices classified as electrochemical capacitors such aselectric double-layered capacitors, pseudocapacitors, and hybridcapacitors can utilize aspects of the present disclosure. Further, it iscontemplated that other existing and yet-to-be-developed battery cellsand battery packs such as lithium-sulfur (Li/S), lithium-air,sodium-air, dual carbon, fluoride-ion, potassium-ion, sodium-ion will beable to utilize aspects of the present disclosure. The previouslyenumerated electrochemical cells and packs are currently used in fullyelectric automobiles, in components of fossil-fuel automobiles, aircraftcomponents, power tools, laptops, mobile phones, mobile computingdevices, household appliances, and entertainment systems. Anyheat-generating electrochemical cell or pack can benefit from theincreased or more stable performance characteristics resulting fromutilizing aspects of the present disclosure.

In general, aspects of the disclosure relate to incorporating a casingof a phase change material containing substance onto, over or otherwisenear a heat-producing individual electrochemical cell or pack so thatheat is pulled away from the cell or pack and stored and/or dissipatedthrough some form of heat transfer substrate to the ambient environment.Described below are specific examples of the constructions of certaincells and packs that can utilize a phase change material substance andstructure and different embodiments of such a composition as used inthese electrochemical cells and packs

FIG. 1A shows a general representation of a lithium-ion battery 100 thatincludes a positive terminal 101 and a negative terminal 102. Astandard, commercially-available cylindrical lithium-ion 18650 cell 100has a nominal voltage of 3.7V and capacity of 1.5 Ah. Though particularreference is made to a specific configuration of a cylindricallithium-ion cell in FIG. 1A, and to a specific configuration of aprismatic lithium-ion cell in FIG. 1B, these references are exemplaryonly and novel aspects of the disclosure are not to be construed aslimited to applying only to these specific kinds of cells. The specificconfigurations and layers of lithium-ion battery cells and electricdouble-layer capacitors disclosed specifically herein are for thepurpose of demonstrating how known battery and other electrochemicalcell configurations can produce heat generally, typically in ranges thatmay be mitigated by embodiments of the present disclosure, and todemonstrate in context the challenges of protecting an individual cellor an entire pack.

FIG. 1A also shows a view of the layers that a lithium-ion cell, (e.g.,a commercially-available 18650 cell) can contain at 103. Various layersof the battery cell as shown at 104 can allow movement an electrolytebetween positive and negative electrodes, (i.e., an anode and acathode). In the example depicted in FIG. 1A, an anode 120 can becomprised of carbon. Its components will be described presently. Acathode 130 can be comprised of lithium manganese oxide. Its componentswill also be described presently. Those skilled in the art willappreciate that a wide variety of materials may be used for anodes andcathodes, and that the materials listed herein are just examples.Current developments in anode and cathode technology may result inanodes and cathodes comprised of polymers or even organic moleculechains. It is contemplated that embodiments of the present disclosuremay be used in conjunction with cells containing these types ofcompositions.

The electrolyte in this particular example is not visually depictedbecause it may flow between the various layers depicted at 104. Examplesof electrolytes in lithium-ion batteries include various lithium saltsin organic solvent. Now turning to the layers depicted in FIG. 1A, andmoving from the outermost layer to the innermost layer, the first layeris the cell can 105, which can be comprised of metal, as is commonlyfound in cylindrical configurations. Other materials are contemplated,such as plastics or polymers, such as those used in many prismaticconfigurations. Alternatively, the outer layer can be comprised of athin metallic or plastic sheet as is commonly used in pouchconfigurations. Next is a first separator layer 106, which can comprisea polymer sheet. Those skilled in the art will appreciate that aseparator can comprise various types of materials, as long as they aresuited to separate the cathode from a metallic exterior and prevent anelectrical short.

Next is the cathode 130, which comprises the first cathode layer 107,second cathode layer 108, and third cathode layer 109. The first andthird cathode layers 107 and 109 can comprise a lithium-metal-oxide,such as lithium permanganate, lithium manganese oxide, or variationsthereof represented by the chemical formula Li_((1+x))Mn₂O₄. A cathodein other types of lithium-ion batteries can comprise, for example,lithium-cobalt (LiCoO₂), lithium-phosphate (LiFePO₄), or lithium-NMC(LiNiMnCoO₂). The second cathode layer 108 can comprise aluminum (Al).108. The next layer is a second separator 110. The second separator 109can comprise the same or similar material as the first separator 106,such as polymer, and its function is to separate the anode and cathodeand prevent an electrical short. Next is the anode 120, which cancomprise a first carbon (C) layer 111, then a copper layer (Cu) 112 anda second carbon layer (C) 113.

FIG. 1B shows a prismatic-shaped lithium-ion battery 150 with a positiveterminal 151 and an adjacent negative terminal 152. Commerciallyavailable prismatic lithium-ion cells can have voltages that include arange between 2.5V and 4.2V, and capacity around 1.2 Ah. Generally, theconstruction of the layers of a prismatic lithium-ion cell can be verysimilar to that of a cylindrical cell. In FIG. 1B, the layers of theprismatic cell include a cell can 155, a separator 156, an anode 157, analuminum layer 158, a separator 159, and the cathode, which can becomprised of a first carbon layer 160, a copper layer 161, and a secondcarbon layer 162.

FIG. 1C shows a general representation of an electrochemical capacitor1100 that includes a positive terminal 1101 and a negative terminal1102. A standard, commercially-available cylindrical electrochemicalcapacitor cell 1100 has a nominal voltage of 2.8V, a capacitance of3400-Farad. Though particular reference is made to a specificconfiguration of a cylindrical electrochemical capacitor in FIG. 1C, andto a specific configuration of a prismatic electrochemical capacitor inFIG. 1D, these references are exemplary only and novel aspects of thedisclosure are not to be construed as limited to applying only to thesespecific kinds of cells. The specific configurations and layers ofelectrochemical capacitor cells disclosed herein are for the purpose ofdemonstrating how known electrochemical capacitor cell configurationscan produce heat in ranges that may be mitigated by embodiments of thepresent disclosure, and to demonstrate in context the challenges ofprotecting a electrochemical capacitor cell or pack.

FIG. 1C also shows a view of the layers that an electrochemicalcapacitor cell, (e.g., a commercially-available Maxwell K2™) cell cancontain at 1103. Various layers of the electrochemical capacitor cell asshown at 1103 can allow movement an electrolyte between positive andnegative electrodes, (i.e., an anode and a cathode). In the exampledepicted in FIG. 1C, an anode 1120 can be comprised of porous carbon.Its components will be described presently. A cathode 1130 can also becomprised of porous carbon. Its components will also be describedpresently. Those skilled in the art will appreciate that a wide varietyof materials may be used for anodes and cathodes, and that the materialslisted herein are just examples. Current developments in anode andcathode technology may result in anodes and cathodes comprised ofpolymers or even organic molecule chains. It is contemplated thatembodiments of the present disclosure may be used in conjunction withcells containing these types of compositions.

The electrolyte in this particular example is not visually depictedbecause it may flow between the various layers depicted at 1103.Examples of electrolytes in electrochemical capacitors include variouslithium-ion salts such as lithium hexafluorophosphate as well asquaternary/alkyl ammonium salts such as tetraethylammoniumtetrafluoroborate or triethyl-methyl-tetrafluoroborate in organicsolvents such as acetonitrile, propylene carbonate, tetrahydrofuran,diethyl carbonate, and y-butyrolactone. Also aqueous electrolytes suchas solutions of sulfuric acid, potassium hydroxide, quaternaryphosphonium salts, sodium perchlorate, lithium perchlorate, and lithiumhexafluoride arsenate are other examples of electrolytes used inelectrochemical capacitors. Ionic liquids, both pure and mixed withorganic solvents such as stated above are another example ofelectrochemical capacitor electrolytes. The outside of anelectrochemical capacitor can comprise a cell can 1140, which can becomprised of metal, as is commonly found in cylindrical configurations.Other materials are contemplated, such as plastics or polymers, such asthose used in many prismatic configurations. Alternatively, the outerlayer can be comprised of a thin metallic or plastic sheet as iscommonly used in pouch configurations.

Now turning to the layers depicted in FIG. 1C, and moving from theoutermost layer to the innermost layer, the first layer is firstseparator layer 1141, which can comprise a polymer sheet. Those skilledin the art will appreciate that a separator can comprise various typesof materials, as long as they are suited to separate the cathode from ametallic exterior and prevent an electrical short. Next is the negativeelectrode, or cathode 1142. Next is a second separator layer 1143,followed by a positive electrode, or anode 1144. Electrodes ofcapacitors generally can be comprised of a high surface area and porousmaterial such as activated carbon, carbon aerogel, graphite, graphene,graphene, carbon nanotubes, carbide-derived carbon and carbonfiber-cloth for electric double-layer type capacitor. Pseudocapacitorelectrodes can comprise of the same carbon materials as listed above aswell as metal oxides and sulfides such as ruthenium oxide, iron oxide,iridium oxide, manganese oxide, iridium oxide, titanium sulfides, andconductive polymers such as polyaniline, polyacetylene, polypyrrole, andpolythiophene. Hybrid capacitor electrodes can comprise of the abovementioned materials from the above description of electric double-layerand pseudocapacitor electrode materials as well as battery intercalationmaterial such as a lithium ion material mentioned for rechargeablelithium-ion batteries such as lithium permanganate, lithium manganeseoxide, or variations thereof represented by the chemical formulaLi_((1+x))Mn₂O₄. A cathode in other types of capacitors can comprise,for example, lithium-cobalt (LiCoO₂), lithium-phosphate (LiFePO₄), orlithium-NMC (LiNiMnCoO₂). Those skilled in the art will appreciate thata positive and negative electrode can comprise various types ofmaterials, and that an electrochemical capacitor can be assembled withsimilarly composed electrodes in a symmetric format or with dissimilarelectrode compositions in an asymmetric format.

FIG. 1D shows a prismatic capacitor cell 1150 with a positive terminal1151 and a negative terminal 1152. Like the cylindrical capacitor cell1100, the prismatic capacitor cell 1150 can be comprised of layers 1163.The layers 1163 can include a cathode 1171, a first separator layer1172, an anode 1173, and second separator layer 1174. The separatorlayers 1172 and 1174 may be comprised of any of the above-referencedmaterials as the separator materials 1141 and 1143 in FIG. 1C.Similarly, the anode 1173 and the cathode 1171 may be comprised of anyof the above-referenced materials as the electrodes 1142 and 1144 inFIG. 1C.

It is known in the art that individual electrochemical cells such as thecylindrical battery cell 100 in FIG. 1A and the cylindrical capacitorcell 1100 in FIG. 1C, and the prismatic cell 150 in FIG. 1B generateheat during charge and discharge. It is known that for a lithium-ioncell, consistent operating temperatures about 60° C. can rapidlydecrease the capacity of the cell. Illustrations of this phenomenon willbe discussed further in this disclosure. Chemical reactions within eachcell increase not only the temperature but also the internal pressure.Each cell can have several internal components that can mitigate heatand pressure buildup to prevent unsafe conditions such as fires orexplosions. These internal components include temperature switches forhigh current, safety vents for high pressure, and a circuit-interruptdevice for overcharging. High current, high pressure, and overchargingcan occur during ordinary operating conditions of a battery.Additionally, extreme current buildup and electrical shorts can occur asa result of the manufacturing process. In some instances, microscopicmetallic particles can inadvertently get mixed into the layers of acell. In another instance, the separators may be unintentionally spacedunevenly. Either of these manufacturing defects can cause too muchcurrent to build up and create a significant electrical short, which cancause the internal battery temperature to heat up rapidly and cause afire or explosion.

Turning now to FIG. 1E, shown is a cell specifically depicting exemplaryinternal protection components common to many lithium-ion cells. Cell180 contains three internal safety features. The first is a PositiveThermal Coefficient (PTC) device 181. In general, the PTC device 181prevents overheating by shutting off excessive current buildup. Thesecond is a circuit interrupt device (CID) 182, which preventsovercharging that would lead to a buildup in internal pressure. In thecase of too much pressure buildup, the third safety feature is a gasrelease vent 183, which, as the name describes, allows gas to vent outthrough a hole near the top of the cell.

Those skilled in the art can appreciate that the layers and safetycomponents of lithium-ion battery cells specifically described hereinare delicate and susceptible to damage by impact. Similarly, other kindsof internal protection components that exist in other types ofelectrochemical cells generally can also be delicate and susceptible todamage by impact. Dents or punctures, for example, can cause the safetycomponents to fail and allow overheating of a cell. They can also causedamage to the separator layers and allow the anode and cathode to comeinto contact with each other, which can cause an electrical short andfire.

Referring now to FIGS. 2A, 2B, 2C, and 2D, shown are individualcylindrical cells associated in packs to create higher voltage and/orcurrent-handling capacity than any single cell. Terminals can beconnected in series in order to reach the desired total voltage (V) orin parallel to reach the desired capacity (Ah) for batteries and energyfor capacitors. FIG. 2A shows an exemplary prior art vehicle batterypack 201. The cells of the battery pack 201 are shown with terminalconnectors 202 connecting the positive terminals 203 of some cells tothe negative terminals 204 of neighboring cells, as is known in the art,in order to create a battery pack with increased voltage as compared tothe voltage of individual cells. In FIG. 2A, each individual cell isencased in a sleeve comprising a plastic or PVC material.

FIG. 2B depicts an arrangement of individual cells in an exemplary priorart power tool battery pack 206. Like the vehicle battery pack of FIG.2A, each cell has a terminal that is linked to at least one other cell'sterminal, though those connections are not all shown. In FIG. 2B, eachindividual cell is encased in a sleeve 207 comprising cardboardmaterial. Sleeves of cardboard, plastic, PVC, and metal have commonlybeen used in the prior art because they offer some minimal level ofprotection against internal and external heat sources, but moreimportantly because their mechanical properties protect againstpunctures and dents. As discussed earlier, the delicate internalcomposition of individual cells can easily be damaged by physical forcessuch as drops, collisions, and punctures.

FIG. 2C shows another exemplary prior art vehicle battery pack 208.Though not shown, the individual cells are linked to each other in asimilar manner as in FIG. 2A. Each individual cell is encased in asleeve 209 comprising a plastic, PVC, or metal material. In addition,the entire battery pack is enclosed in a housing 210. The housing 210can protect the battery pack 208 from impact and separation, and mayprovide ease of use for transport and installation, and may also serveother functions not immediately apparent from the figure, such aselectronic management of cell performance. For example, many batterypacks contain external protection circuits that cut off voltage toindividual cells if their voltages or temperatures get too high. Becauseprotection circuits monitor each individual cell, battery packscontaining dozens of cells can be complex and expensive to manufacture.Further, the protection circuits inhibit excessive voltage only fromoutside sources, such as a faulty charger or an external electricalshort.

FIG. 2D shows another exemplary prior art pack 215 that isshrink-wrapped in a plastic or PVC-type film 216. Like the prior artpacks shown in FIGS. 2A-2C, the individual terminals of the cells may belinked together to increase voltage, capacity, or energy.Shrink-wrapping is commonly used in the prior art to hold individualcells in a particular configuration, but because plastic and PVC-typefilms are typically used in shrink-wrapping applications, the thermalmanagement and mechanical protection properties of these films areminimal.

In sum, individual cells face detrimental effects from heat from bothinternal and external sources. The internal sources include the heatgenerated from normal charge and discharge as well as any manufacturingdefects that can cause current buildup and internal shorts (i.e.,thermal runaway of an individual cell). External sources includephysical stresses such as ambient heat (caused by events such as leavinga mobile device in the sun), extreme cold, and physical impact. Externalsources can also include excessive applied voltage, such as that causedby a faulty charger or an external electrical short. The most extremeexternal heat source can be the thermal runaway and fire of anothercell, which can in turn cause the thermal runaway of other cells withina pack.

Various embodiments of the present disclosure comprise elastomers andmaterials whose properties may be referred to as elastomeric. FIG. 3depicts high level views of an elastomer, which may be comprised ofblock copolymers with “hard” (or rigid) segments 301 and 301A and “soft”(or flexible) segments 302 and 302A. The hard segments can combine toprovide hardness, rigidity, stiffness, toughness, stability and chemicalresistance. The hard segments can be made of high glass transitiontemperature materials, crystallizable materials where the segments willform stable crystalline domains, or functional crosslinkable materialsin which formed crosslinks will hold the domains stable and rigid. Thecrosslinks may be through hydrogen bonding. The soft segments aregenerally in an amorphous or rubbery phase and not aligned orinteracting with other soft segments. This allows the segments to beflexible, free moving and have good elongation characteristics. The softsegments can be comprised of low glass transition temperature materials,amorphous (non-crystalline) materials, and can generally have low or nocrosslinking. The hard or soft segments can be of different or the samechemical makeup. For example, a polypropylene elastomer can consist ofsyndio or isotactic polypropylene segments allowing for hard crystallinesegments compared to the soft segment of randomly or atactic polymerizedpolypropylene. The segments can have different melting points due to thedifferent phases or crystalline structures. Depending on the softsegment or hard segment concentration, chemistry, molecular weight,etc., the polymer can have a continuous hard phase with a dispersed softphase, or a continuous soft phase with dispersed hard phase if the hardsegments are in low concentration. The morphology developed duringpolymer or part production, the miscibility of the phases, the size ofthe dispersed phases and their characteristics strongly affect the finalproperties of the polymer. In certain embodiments of the disclosure, theabove-mentioned compositions can result in desirable hardness propertiessuitable for protecting an electrochemical cell from denting orpuncturing by an outside force. For example, the compositions may resultin a Shore A hardness of greater than 85 and a Shore D hardness ofgreater than 25, per ASTM D2240. Additionally, the above-mentionedcompositions may result in desirable elasticity properties suitable forexpanding and contracting with a particular electrochemical cell orpack. For example, the compositions may result in a flex modulus ofgreater than 15 pounds per square inch and a break elongation of greaterthan 20%.

Turning now to FIG. 4A, shown is an embodiment of the disclosure inwhich a sleeve 400 encases A standard lithium-ion 18650 battery cell405. The solid sleeve 400 can comprise one or more PCMs within a TMMmatrix. Various materials can be used in the construction of a solidsleeve in accordance with the present disclosure, and examples of suchmaterials are described in greater detail throughout the disclosure. Itis contemplated that sleeves of similar configurations may be of varioussizes in other embodiments, in order to fit other sizes of batteries andother electrochemical cells.

FIG. 4B shows an embodiment of the disclosure in which a rectangularcasing 410 encases a rectangular or prismatic electrochemical cell 415.Various materials can be used in the construction of a solid sleeve inaccordance with the present disclosure, and examples of such materialsare described in greater detail throughout the disclosure. It iscontemplated that sleeves of similar configurations may be of varioussizes in other embodiments, in order to fit other sizes of batteries andother electrochemical cells. In the embodiment shown, at least one endof the rectangular casing 410 is open to allow the exposure of theterminals. The opposite end may be closed.

FIG. 4C depicts embodiments of casings for packs of electrochemicalcells. A casing 421 may comprise multiple individual sleeves 420 whichare attached to each other, forming complete cylinders of PCM-TMMmaterial around each cell. This configuration possibly can createinterstitial spaces between each individual sleeve 420, which may beleft empty to allow dissipation into the ambient environment, or whichmay be filled with another thermal conductive filler. A casing 425 showsthe casing 421 containing multiple battery cells 426 with individualsleeves 424. In another embodiment, a casing 423 may be entirelypre-formed to fit a certain number of cells in a pack. Each cell may beencased by an individual casing section 422, but the entire casing 423may not have any interstitial air spaces. That is, the casing 423 mayhave PCM-TMM material in all of the space between each individual cell.It is contemplated that various shapes and sizes of the pack casingsdepicted in FIG. 4C may be used without departing from the scope of thepresent disclosure.

FIG. 4D shows additional embodiments of electrochemical cell casingsthat are rectangular in shape and which are configured to receive andretain a plurality of electrochemical cells. A side perspective viewshows the rectangular casing 430 with a plurality of receptacles 432that has smooth surfaces on each side. A top view shows the rectangularcasing 435 with the plurality of receptacles 437 spaced out fairlyuniformly.

FIG. 5A shows an exemplary top view of an electrochemical cell 505encased in a sleeve 500 in a similar fashion to the exemplary sleeve 400depicted in FIG. 4A, with certain features drawn in an enlarged mannerfor the purposes of illustration. The sleeve 500 can specificallycomprise a polymer matrix. The polymer matrix may comprise anelastomeric thermal management material (TMM) 502 that is blended withone or more PCMs 501. PCMs 501 as depicted in FIG. 5A are represented asspherical and dispersed non-uniformly throughout the elastomeric TMM502. However this depiction of PCMs 501 is for purposes of illustrationonly; in actual embodiments, the PCM 501 may be non-spherical, may bedispersed uniformly, and may be larger or smaller in relation to thedepiction. Additionally, the thickness of the sleeve 500 in relation tothe battery cell 505 is not necessarily to scale. The elastomeric TMM502 may comprise polyolefin copolymers such as copolymers ofpolyethylene with any C₃-C₃₀ α-olefin, or vinyl acetate, other vinylmonomers such as styrene or its analogues, acrylate or methacrylatemonomers, vinyl ether monomers, vinyl ester monomers, acrylonitriles,rubbers and copolymers made from isoprene, butyl, etc., or combinations,blends, mixtures thereof. The polymers or copolymers can be random orblock copolymers.

The elastomeric TMM 502 can comprise a polymer elastomer made frompolyesters, silicon rubbers or polyurethanes. Non-inclusive examples ofthese are Hytrel® polyesters from DuPont®, Kraton® SEBS, SEPS, SBS orSIS block copolymers, Septon™ and other elastomers by Kuraray Co.,Spandex® type polyurethanes and RTV or LTV type silicon rubbers. Tofurther improve the elastomeric properties of the polymer matrix, thematrix (i.e., the elastomeric TMM 502 and the PCMs 501) can becrosslinked for improved elastomeric properties with 0.05-1.0 crosslinkper polymeric chain.

Because of the range of temperatures within which lithium-ion cellsgenerate heat in normal operation, the sleeve 500 may contain at leastone PCM 501 with transition temperature in some embodiments between0-100° C., and in other embodiments specifically between 40-80° C. ThePCM may have >10 J/g latent heat content in some embodiments and inother embodiments specifically >60 J/g. In yet other embodiments, thePCM may have a higher transition temperature range, such as between 25°C. and 140° C., and a latent heat of >2 J/g. In the example of FIG. 5the PCM 501 is a microencapsulated PCM (mPCM) but can also be a raw orotherwise unencapsulated PCM such as a pPCM (polymeric PCM) or an fpPCM(functional polymeric PCM). In some embodiments, there may be more thanone type of PCM within the sleeve 500. In other embodiments, asubstantially homogenous composite polymeric PCM may comprise the entiresleeve.

Because of the need for close contact between the sleeve 500 and theouter surface of the battery cell 505, the elastomeric polymer matrixcan have good thermal elasticity properties characterized by lowcoefficient of thermal expansion (CTE) and high fatigue or creepresistance. In the embodiment depicted, these values can be a CTE of<200 ppm (per ASTM E228) and no fatigue failure (per ASTM D7791, MethodA, 2 Hz, 2 mPa, Stress, sinusoidal wave.) Such properties can minimizethe likelihood of air gaps forming or expanding between the sleeve 500and the cell 505 over time as the cell 505 undergoes charge/dischargecycles.

Still referring to FIG. 5A, a gel layer 503 may be used, as discussedpreviously in this disclosure, to fill any air gaps between the sleeve500 and the cell 505. The gel 503 may also act as a lubricant andfacilitate the application of the sleeve 500. The gel 503 may becharacterized as a grease or a wax in certain embodiments. Though thegel 503 as depicted in FIG. 5 is a relatively thick layer, it isdepicted as such for illustration and is not necessarily to scale. Thegel 503 may be a lower molecular weight version of the same polymermatrix, TMM, and/or PCM blends that comprise the sleeve 500. Incomparison to the properties of the sleeve 500, the gel 503 may have ahigher percentage of conductivity additives (i.e., graphene, graphite,carbon fibers, metals, etc.) to improve the thermal transport.

As previously discussed, impact resistance can protect the internalcomponents of the cell 505 from damage. In the embodiment depicted, thesleeve 500 can have hardness and stiffness properties that enable suchprotection. Additionally, the hardness and stiffness properties canprevent deformation of empty sleeves from stacking during shipping.Therefore, the sleeve 500 may have a Shore A hardness of >85 and a ShoreD hardness >25 (per ASTM D2240). Additionally, the sleeve 500 may have aflex modulus of >15 psi (per ASTM D790) and a break elongation >20% (perASTM D638). The foregoing properties of the sleeve 500 as describedherein may be accomplished by one or more of the chemical structuresdescribed throughout this disclosure.

Another embodiment of the disclosure may be achieved as depicted in FIG.5B. FIG. 5B shows a battery cell 515 that is similar to battery cells405 and 505 of FIGS. 4A and 5A, respectively. A battery casing sleeve510 in the embodiment depicted can be applied to the cell 515 as a filmor tape wrapped around the cell 515 multiple times. A layer of the filmor tape is depicted at 508. The film or tape may be comprised of apolymer matrix with similar properties as described with reference tothe sleeve 500 in FIG. 5, but may be thinner. The film or tape may betapered in thickness at one or more of its ends in order to facilitateapplication. Any of the materials disclosed herein which may be used tocomprise sleeve 500 in FIG. 5 may also be used to comprise the film ortape.

An adhesive 507 may be used to initially attach the first layer of filmor tape to the outside of the cell 515. The adhesive 507 may becomprised of lower molecular weight versions of the TMM or PCM of thefilm or tape itself. The adhesive 507 may be a backing to the film ortape itself, such that each wrapping of the film or tape around thecircumference of the cell 515 results in a layer of adhesive and thepolymer matrix. The adhesive may have similar thermal managementproperties as the polymer matrix itself. It is contemplated that certaincompositions of the polymer matrix film or tape may have intrinsic“sticky” or “tacky” properties, such that no additional adhesivematerial is required to layer the film or tape onto itself. The film ortape may also have “shrink wrap” properties, such that the film or tapeis supplied in an oriented form (polymer chains are aligned) and whenheated the film or tape will shrink (due to polymer chains randomizing),adhere and fill any air gaps either within the tape/film layers or atthe battery surface. An advantage to the film or tape embodiment of thesleeve 510 is that the thickness of the sleeve can be adjusted for theparticular application. That is, higher-heat generating applications canuse more film or tape to manage the thermal properties of the cells usedtherein. Device manufacturers or end users could customize the thermalmanagement as required. Various embodiments of film and tapeapplications, including compositions and methods of manufacturingthereof, are fully disclosed in the co-owned and co-pending applicationentitled “Thermal Management Films Containing Phase Change Materials,”U.S. patent application Ser. No. 14/614,236, filed on Feb. 4, 2015(Attorney Docket No. OUTT.049.00US), which is incorporated herein byreference in its entirety.

For the purposes of this disclosure, the term “temperature managementmaterial (TMM)” may refer to any single material or composition ofmultiple materials that have some temperature management properties. Forexample, an entire sleeve can be said to be made of temperaturemanagement material, or just a gel by itself can be a temperaturemanagement material. Certain materials that have relatively loweffectiveness for regulating temperature in comparison to othermaterials with which they are combined may be referred to as “thermalconductive fillers.” That is, these fillers have some temperaturemanagement properties, but they may be included in a mixture becausetheir other properties are beneficial; properties such as energyconduction, mechanical strength, fire resistance, rheology, viscosity,elasticity, etc. These thermal conductive fillers may be liquid orsolid. PCMs may be referred to as temperature management materialsthemselves, but will generally not be referred to as thermal conductivefillers because they have exceptional temperature management qualities.As will be described in further detail below, there are various types ofPCMs.

FIGS. 6A-6C show various embodiments of an elastomeric temperaturemanagement material in various arrangements with PCMs that may be usedto form embodiments of the disclosure in matrix forms and layered forms.FIG. 6A shows a uniform mixture (or matrix) 600 of a PCM 602 and anelastomeric TMM 604. In the example of FIG. 6A, the PCM 602 is amicroencapsulated PCM (mPCM) but can also be a raw or otherwiseunencapsulated PCM such as a pPCM (polymeric PCM) or an fpPCM(functional polymeric PCM). However the phase change material isincorporated into the matrix 600, in the example of FIG. 6A, the matrixis a uniform substance with some level of homogeneity to the material.There are no specific layers within the example of FIG. 6A.

With reference to FIG. 6B, a layered composition 620 is shown thatincludes several layers. The layered composition may form a part of asleeve such as the sleeve 500 depicted in FIG. 5A. For example, a one ofthe layers depicted in FIG. 6B may be the innermost or outermost layerof a sleeve. Alternatively, all the layers depicted in FIG. 6B could bedisposed completely within a sleeve, having no contact with a batterycell or the ambient environment. In FIG. 6B, a layer 622 is formed froma thermal conductive filler such as an elastomeric TMM, a layer 624 isformed from a first phase change material, and a layer 626 is formedfrom a second phase change material. The layers 624 and 626 may each beany of an mPCM, pPCM, or fpPCM or the layers 624 and 626 may becombinations or blends of one or more of these types of phase changematerials. In addition, each of layer 624 and 626 can utilize any of thePCM materials discussed herein in various combinations that may benecessary to fit a specific temperature control scenario. For example,certain electrochemical cells may generate more heat, or have a steeperheating curve profile and thus warrant the use of PCMs that have higherlatent heat values or higher PCM loading requirements in order toeffectively manage the temperature changes that occur in thoseelectrochemical cells. Other applications may have more subtletemperature change profiles and may not demand PCMs with such largelatent heat values and can thus utilize lower loading amounts.

With reference to FIG. 6C, another layered composition 640 is shown thatalso includes several layers. A layer 642 is formed from an elastomericTMM, a layer 644 is formed from a first phase change material, and alayer 646 is formed from a second phase change material. As with theexample of FIG. 6B, the layers 644 and 646 may each be any of an mPCM,pPCM, or fpPCM or the layers 644 and 646 may be combinations or blendsof one or more of these types of phase change materials. In addition,each of layer 644 and 646 can utilize any of the PCM materials discussedherein in various combinations that may be necessary to fit a specifictemperature control scenario. In the embodiment and example of FIG. 6C,layer 644 is shown utilizing microcapsules 645. These microcapsules maybe within a polymeric binder 647 (with or without its own PCM and latentheat qualities).

FIGS. 7A-15B will be discussed later in this disclosure.

FIGS. 16A-16C show other layering options that may be utilized inconstructing the structure (e.g., sleeve or tape) for temperaturemanagement and heat dissipation. As exemplified in FIGS. 16A-16C, anycombination of these different layers are also possible. In FIGS.16A-16C, each of L1 through L8 represent different layers within asleeve 500 or 510 or different regions within a discrete portion of asleeve 500 or 510. It should be understood that many differentcombinations of these layers are possible and it is not intended tolimit the disclosure to any of the physical structures depicted by FIGS.16A-16C. These are merely representative of several of thepossibilities.

Use of PCMs and Other Thermal Management Materials

The sections above describe various compositions and other materialsthat may be used in connection with the electrochemical cells and packsthat may benefit from the temperature control and thermal managementaspects of the present disclosure. However, by referring to any of thespecific structural embodiments or any of the precise and specificchemical compositions (above or further in this disclosure), it is notintended to limit the scope of the claims to any one in particular. Tothe contrary, the specification is arranged such that one of skill inthe art could combine one or more of the cells and battery packsdescribed herein with one or more of the chemical compositions describedherein in order to create a configuration that worked for a specificpurpose.

While the above description of phase change technology and the differenttypes of chemicals and other materials useful in temperature regulationis generally applicable and relevant to aspects and embodiments of thepresent disclosure, there are other aspects and unique features thatfind particular relevance in electrochemical cell thermal managementapplications.

Thermal Management Materials (TMM) for Electrochemical Cell TemperatureControl

PCMs are very advantageous for use as thermal management materials inelectrochemical cells and packs in that the high crystallinity allowsfor a combination of good thermal conductivity, high latent heatcapacity and energy absorption all leading to improved heat management,lower heat buildup, lower rate of degradation of the cell, and lowerlikelihood of thermal runaway.

Air is a very poor thermal conductor and therefore air spaces or airgaps anywhere within the TMM is not preferred. Air gaps such as betweenthe individual cells and thermal management materials, cracks or voidswithin the TMM, voids or gaps between particles and the TMM composite ormatrix material, etc. are all problematic for good thermal conductivity.For example, sliding a sleeve or wrapping a tape around a batteryrequires that two solid surfaces be brought together into intimatecontact. Unfortunately, no matter how well prepared, solid surfaces arenever really flat or smooth enough to permit intimate contact. Allsurfaces have a certain roughness due to microscopic hills and valleys.Superimposed on this surface roughness is a macroscopic non-planarity inthe form of a concave, convex or twisted shape. As two such surfaces arebrought together, only the hills of the surfaces come into physicalcontact. The valleys are separated and form air-filled gaps. Since airis a poor conductor of heat, it should be replaced by a more conductivematerial to increase the joint conductivity and thus improve heat flowacross the thermal interface. Adding to the difficulty of creatingcontact between solid surfaces, certain characteristics ofelectrochemical cells create additional problems. For example, evenstandard-sized commercially available batteries, such as a lithium-ion18650, may vary slightly in size from one manufacturer to another.Therefore, standard-sized battery sleeves may not fit certain batteriesas well as others. Additionally, the batteries themselves go throughmultiple cycles of heating and cooling, resulting in the slightexpansion and contraction of the cell itself. It follows that anymaterial in close contact with the battery will also go through multiplecycles of expansion and contraction, and any materials that do not havegood elastomeric properties might lose contact over time. The thermalmanagement materials should have good rheological characteristics andsurface wetting to have good “gap-filling” properties, i.e. the abilityto flow, wetout and fill gaps, crevices, cracks, etc. to reduce air gapsand improve thermal movement. These TMM flow properties can beformulated into the material through the use of additives or designedinto the TMM molecules. TMMs can also be used in a liquid form such as agel or a grease to maintain contact between a solid TMM and the battery.

TMMs should also have good adhesive, tack, or bonding properties toprevent the loosening of contact between the TMM and the battery cellswhen the device being powered is dropped, damaged, impacted or exposedto high or low temperatures.

For electrochemical cell and pack applications, TMMs should also havegood impact and puncture resistance. As discussed previously, overheatedcells in direct contact with each other can cause thermal runaway,leading to fires and explosions. Additionally, an electrochemical celldamaged by impact or puncture can easily be ignited itself, and cancause further ignition and explosions of nearby cells or othercombustible materials. Electrochemical packs in vehicles can create arisk of fires if the vehicles are involved in collisions and the packsare impacted. The presence of combustible components in vehicles makesthe necessity for physical protection of electrochemical cells and packsapparent.

Current electrochemical device thermal management materials have manydisadvantages such as poor latent heat properties, poor heat sinkproperties in the appropriate temperature range, poor gap/void fillingproperties, poor rheology, etc.

FIGS. 17-20 show graphs that illustrate the benefits of using aspects ofthe present disclosure in connection with battery cells and the abilityof embodiments of the present disclosure to moderate the buildup of heatduring various charging, discharging, and cycling functions of cells.

FIG. 17 is a graph that illustrates the degradation of capacity inlithium-ion 18650 cells over a number of cycles in relation totemperature. In the experiment represented by this graph, the y-axis at1710 shows a cell's capacity as measured by milliampere hours (mAh),from 0-18. The x-axis at 1715 shows the number of cycles each cellcycles through in the experiment, from 0-140. The graph line at 1720represents the capacity of a cell as it cycles through up to 140 cycleswhile its temperature is maintained at 25° C. The graph line at 1725shows the capacity of a cell as it cycles through up to 140 cycles whileits temperature is maintained at 60° C. As illustrated by the graph lineat 1720, the cell at 25° C. only experienced minimal degradation—fromabout 16 mAh to 14 mAh over 140 cycles. In comparison, the cell at 60°C. experienced significant degradation—from about 16 mAh to about 5 mAhover 140 cycles. This graph illustrates that there are performance andlongevity benefits to be gained by lowering the temperature of alithium-ion 18650 cell throughout cycles.

FIG. 18 is a graph illustrating how a PCM-containing TMM formulation wasable to reduce operating temperatures of cells being discharged. Forease of reference, the PCM-containing TMM sleeves used in theseexperiments will be referred to as PCM-TMM sleeves. In the experimentrepresented by this graph, three individual lithium-ion 18650 cells weredischarged at a continuous rate of 20A for a period of eight minutes,the time being represented on the x-axis. To test the effectiveness ofPCM-TMM sleeves to manage surface temperatures of lithium-ion batteriesin particular, a single 20A discharge testing regime was undertakenusing a resistive load tester. This tester contained a circuit in whichtwo resistors of 0.33Ω were wired in parallel and connected to a batteryholder containing the lithium-ion battery. Testing was started andstopped manually via a circuit interrupt switch. Voltage was monitoredthroughout the test via a digital multimeter with leads attached to theterminals of the battery holder. All tests began with an open circuitpotential of 4.1V for each battery and stopped once closed circuitvoltage reached 2.4V. The surface temperatures of each cell weremonitored via an infrared camera as well as a thermocouple attached to adigital readout to directly measure cell surface temperatures.Temperature measurements were taken every minute from the start to theend of each test.

Each battery had different temperature controls. A first battery cellwas uncoated, meaning it had no sleeve surrounding it. Its temperatureprofile is represented on the graph as “uncoated.” A second cell wasencased in a control polymer sleeve, meaning that the polymer did nothave specifically optimized thermal management qualities and did notcontain any PCMs. The particular polymer used in this control sleeve wasepoxy, which has been used in the prior art to physically protectbattery cells. Its temperature profile is represented on the graph as“control sleeve.” The control (epoxy only) sleeve and PCM-TMM sleevewere formed around the battery using an epoxy composite. The controlsleeve was only epoxy and no PCM, whereas the PCM-TMM sleeve contained45% microencapsulated docosane (an mPCM). Both sleeves weighedapproximately 12 grams.

As shown in the graph of FIG. 18, the results show that the temperatureof the PCM-TMM sleeved batteries, shown at graph line 1809, reached anaverage temperature of 50° C. at 8 minutes. In comparison, the controlsleeved cells reached an average end of discharge surface temperature of57° C., shown at graph line 1805. The uncoated cell, shown at graph line1801, reached a temperature of nearly 72° C. after eight minutes ofcontinuous discharge.

FIGS. 19 and 20 show the results of a different experiment, which usedbattery charge and discharge testing, undertaken to evaluate thetemperature management properties of a PCM-TMM sleeve and the effect oftemperature management (e.g., lower temperatures) on battery capacityretention. An 18650 Li-ion battery with a 1.95 Ah rated capacity wasencased in a PCM-TMM sleeve and compared to an 18650 Li-ion controlbattery without a sleeve. Both batteries underwent 700 charge anddischarge cycles. Battery surface temperatures and battery charge anddischarge capacity were measured. The PCM-TMM sleeve was comprised of50% microencapsulated docosane in 50% polyolefin copolymer elastomer.The sleeve weighed 7.3 grams and fit snugly around the cell. The controlcell and the PCM-TMM-sleeved cell were tested on separate batteryholders with thermocouples attached to the surface of each cell. For thePCM-TMM-sleeved cell, the thermocouple was placed underneath the sleevein order to measure the cell surface temperature directly. A computercontrolled galvanostat/potentiostat with precise voltage and currentcontrol was used to compare the charge and discharge capacity retentionbehavior between the control cell and the PCM-TMM-sleeved cells. Theresults of the discharge capacity retention will be described presentlywith reference to FIG. 20. This instrument was also used to determinethe phase change reliability via real-time monitoring of attachedthermocouples attached to the surface of each cell. Phase changereliability refers to the capacity of the PCM to be cycled indefinitelywithout losing its temperature management properties. That is, a PCMwith good phase change reliability is capable of absorbing heat,melting, releasing heat, and crystallizing over and over again.

The testing protocol consisted of the following steps: First, the cellsrested for one minute before charging at 1.95A until the voltage of eachcell reached 4.2V. Next, the cells trickle charged until the current ofeach cell dropped below 0.25A. Next, the cells rested for 2 minutesbefore discharging at 20A until voltage of 2.5V was achieved by eachcell. Next, the cells rested for 15 minutes before looping back to thecharge cycle. This series of steps was repeated 700 times. FIG. 19 showsthe end of discharge surface temperature for the control andPCM-TMM-sleeved cell after each cycle along two graph lines. Thetemperature of the control cell is depicted by graph line 1901 and thetemperature of the PCM-TMM-sleeved cell is depicted by graph line 1905.The data, represented on the graph of FIG. 19, shows that the PCM-TMMsleeve kept the battery surface approximately 17° C. cooler for eachcycle.

FIG. 20 shows the discharge capacity retention of the control cell andthe PCM-TMM-sleeved cell over the 700 cycles of charge and discharge.The graph line at 2001 depicts the discharge capacity retention of thecontrol cell, and the graph line at 2005 depicts the discharge capacityretention of the PCM-TMM-sleeved cell. As shown by the data, thedischarge capacity of the PCM-TMM-sleeved cell remains greater than thedischarge capacity of the control cell during all cycles, and thedifference between the two cells becomes greater as the number of cyclesincreases. The difference demonstrates that lower battery temperatureslead to less battery degradation and longer life, as shown by the higherretention in discharge capacity of the PCM-TMM-sleeved cell.

It is contemplated that different types of cells, and cells used indifferent applications (i.e., higher voltage, higher discharge, longertime periods, more frequent cycles) than the cells and applications inthese experiments may require different formulations of PCM-containingTMMs. Various ways of achieving the desired thermal managementproperties for particular cells and applications are discussedthroughout this disclosure. The specific formulations of PCM-TMM sleevesdescribed in the experiments of FIGS. 17-20 are merely exemplaryembodiments of the disclosure, and should not be construed as limitingthe scope of the disclosure.

As described in general terms above and in the definition section, theterm “phase change material” refers to a material that has thecapability of absorbing or releasing heat to adjust heat transfer at orwithin a temperature stabilizing range. A temperature stabilizing rangecan include a specific transition temperature or a range of transitiontemperatures. In some instances, a phase change material can be capableof inhibiting heat transfer during a period of time when the phasechange material is absorbing or releasing heat, typically as the phasechange material undergoes a transition between two states. This actionis typically transient and will occur until a latent heat of the phasechange material is absorbed or released during a heating or coolingprocess. Heat can be stored or removed from a phase change material, andthe phase change material typically can be effectively recharged by asource of heat or cold. For certain implementations, a phase changematerial can be a mixture of two or more materials. By selecting two ormore different materials and forming a mixture, a temperaturestabilizing range can be adjusted for any desired application. Theresulting mixture can exhibit two or more different transitiontemperatures or a single modified transition temperature whenincorporated in the articles described herein.

PCMs that can be used include various organic and inorganic substances.Organic PCMs may be preferred for the embodiments disclosed herein.Examples of phase change materials include hydrocarbons (e.g.,straight-chain alkanes or paraffinic hydrocarbons, branched-chainalkanes, unsaturated hydrocarbons, halogenated hydrocarbons, andalicyclic hydrocarbons), alkanes, alkenes, alkynes, arenes, hydratedsalts (e.g., calcium chloride hexahydrate, calcium bromide hexahydrate,magnesium nitrate hexahydrate, lithium nitrate trihydrate, potassiumfluoride tetrahydrate, ammonium alum, magnesium chloride hexahydrate,sodium carbonate decahydrate, disodium phosphate dodecahydrate, sodiumsulfate decahydrate, and sodium acetate trihydrate), waxes, oils, water,fatty acids (caproic acid, caprylic acid, lauric acid, myristic acid,palmitic acid, stearic acid, arachidic acid, behenic acid, lignocericacid and cerotic acid, etc.), fatty acid esters (methyl caprylate,methyl caprate, methyl laurate, methyl myristate, methyl palmitate,methyl stearate, methyl arachidate, methyl behenate, methyl lignocerate,etc.), fatty alcohols (capryl alcohol, lauryl alcohol, myristyl alcohol,cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol,lignoceryl alcohol, ceryl alcohol, montanyl alcohol, myricyl alcohol,and geddyl alcohol, etc.), dibasic acids, dibasic esters, 1-halides,primary alcohols, secondary alcohols, tertiary alcohols, aromaticcompounds, clathrates, semi-clathrates, gas clathrates, anhydrides(e.g., stearic anhydride), ethylene carbonate, methyl esters, polyhydricalcohols (e.g., 2,2-dimethyl-1,3-propanediol,2-hydroxymethyl-2-methyl-1,3-propanediol, ethylene glycol, polyethyleneglycol, pentaerythritol, dipentaerythritol, pentaglycerine,tetramethylol ethane, neopentyl glycol, tetramethylol propane,2-amino-2-methyl-1,3-propanediol, monoaminopentaerythritol,diaminopentaerythritol, and tris(hydroxymethyl)acetic acid), sugaralcohols (erythritol, D-mannitol, galactitol, xylitol, D-sorbitol),polymers (e.g., polyethylene, polyethylene glycol, polyethylene oxide,polypropylene, polypropylene glycol, polytetramethylene glycol,polypropylene malonate, polyneopentyl glycol sebacate, polypentaneglutarate, polyvinyl myristate, polyvinyl stearate, polyvinyl laurate,polyhexadecyl methacrylate, polyoctadecyl methacrylate, polyestersproduced by polycondensation of glycols (or their derivatives) withdiacids (or their derivatives), and copolymers, such as polyacrylate orpoly(meth)acrylate with alkyl hydrocarbon side chain or withpolyethylene glycol side chain and copolymers including polyethylene,polyethylene glycol, polyethylene oxide, polypropylene, polypropyleneglycol, or polytetramethylene glycol), metals, and mixtures thereof. Anycombination of natural alcohols, natural fatty acids, sugars, cellulosesand natural glycols can be combined to yield PCMs. General formulas suchas the following, where m or n can be 0-100:

Polymerized alcohols such as polyvinyl alcohol, polyglycerols (mol. wt.of 100-10,000) or multifunctional alcohols esterified with various fattyacids.

Paraffinic PCMs may be a paraffinic hydrocarbons, that is, hydrocarbonsrepresented by the formula C_(n)H_(n+2), where n can range from about 10to about 44 carbon atoms. PCMs useful in the disclosure includeparaffinic hydrocarbons having 13 to 50 carbon atoms. For example, themelting point of a homologous series of paraffin hydrocarbons isdirectly related to the number of carbon atoms as shown in the followingtable:

No. of Melting Carbon Point Paraffinic Hydrocarbon Atoms (° C.)n-Octacosane 28 61.4 n-Heptacosane 27 59.0 n-Hexacosane 26 56.4n-Pentacosane 25 53.7 n-Tetracosane 24 50.9 n-Tricosane 23 47.6n-Docosane 22 44.4 n-Heneicosane 21 40.5 n-Eicosane 20 36.8 n-Nonadecane19 32.1 n-Octadecane 18 28.2 n-Heptadecane 17 22.0 n-Hexadecane 16 18.2n-Pentadecane 15 10.0 n-Tetradecane 14 5.9 n-Tridecane 13 −5.5

Use of Polymeric Phase Change Materials (PPCMs) and Functional PolymericPhase Change Materials (FP-PCMs) as TMMs Reactive Functional Groups

Examples of suitable reactive functional groups include functionalgroups such as acid anhydride groups, amino groups, N-substituted aminogroups and their salts, amide groups, imine groups, imide groups, azidegroups, azo groups, amine-formaldehyde groups, carbonyl groups, carboxygroups and their salts, cyclohexyl epoxy groups, epoxy groups, glycidylgroups, hydroxy groups, isocyanate groups, cyanate groups, urea groups,aldehyde groups, ketone groups, ester groups, ether groups, alkenylgroups, alkynyl groups, thiol groups, disulfide groups, silyl or silanegroups, halogenated leaving groups, peroxide groups, salt groups, groupsbased on glyoxals, groups based on aziridines, groups based on activemethylene compounds or other b-dicarbonyl compounds (e.g.,2,4-pentandione, malonic acid, acetylacetone, ethylacetone acetate,malonamide, acetoacetamide and its methyl analogues, ethyl acetoacetate,and isopropyl acetoacetate), halo groups, hydrides, or other polar or Hbonding groups and combinations thereof.

Further details of the variety of examples of reactive functions andfunctional groups that may be used in accordance with one or moreaspects of the present disclosure can be found in commonly owned U.S.Pat. Nos. 8,404,341 and 8,221,910, the details of which have beenincorporated by reference into this disclosure. It should be clearlyunderstood that by providing examples of specific compositions andmethods in the later part of this description, applicant does not intendto limit the scope of the claims to any of those specific composition.To the contrary, it is anticipated that any combination of thefunctional groups, polymeric phase change materials, and articlesdescribed herein may be utilized to achieve the novel aspects of thepresent disclosure. The claims are not intended to be limited to any ofthe specific compounds described in this disclosure or any disclosureincorporated herein.

Polymeric Phase Change Materials and Reactivity

Several publications referenced herein deal with polymeric PCMs (pPCM),which present an intermediate case between the solid-liquid PCMs and thesolid-solid PCMs. pPCMs are solid both prior to phase change and afterit. The difference is in their degree of structure. At lowertemperatures, that degree is greater than that at the elevatedtemperature, so that at a temperature of phase change, pPCM convertsfrom the more structured form into its less structured one. Typically,in the more structured form, some sections of the polymer are betteraligned and more closely compacted. The better aligned sections resemblecrystallites. Therefore, the phase change on heating pPCM is alsoreferred to as change from a more crystallized form to a lesscrystallized form. Differently put, at the elevated temperatures (abovethe transition temperature), pPCMs are essentially amorphous. At thelower temperatures (below the transition temperature) they have a degreeof crystallinity. Similarly, the changes on heat absorption and on heatrelease could be referred to as decrystallization and recrystallization,respectively. The related enthalpy could also be referred to as enthalpyof decrystallization.

Typically, pPCMs have sections that are capable of being better alignedand more closely compacted. Such sections could be referred to ascrystallizable sections. In some embodiments, the functional polymericPCM described herein in accordance with various aspects of the presentdisclosure comprises at least one such crystallizable section. Accordingto an embodiment of the disclosure, the polymer comprises a backbone andside chains. Preferably, the side chains form a crystallizable section.

Functional Polymeric Phase Change Materials (fpPCMs)

As used here, the term “reactive function” means a chemical group (or amoiety) capable of reacting with another chemical group to form acovalent or an electrovalent bond, examples of which are given above. Insome embodiments such reaction is feasible at relatively lowtemperatures, e.g. below 300, in other embodiments, below 200° C., inother embodiments, below 100° C., and at conditions suitable forelectrochemical device applications. As used herein the term “carrying afunction” and obvious variations of this term, means having a functionbound to it, e.g. covalently or electrovalently.

The reactive function could be placed on (carried on or covalently boundor electrovalently bonded to) any part of the fpPCM molecule, e.g. on aside chain, along the backbone chain or on at least one of the ends ofthe backbone chain or side chain. According to various embodiments ofthe disclosure, the fpPCM comprises multiple reactive functions andthose functions are spread at substantially regular intervals,stereospecifically (i.e. isotactic, syndiotactic, or atactic, etc.) orrandomly along the molecule, e.g. along the backbone chain. Anycombination of these is also possible.

The molecular weight of an fpPCM in some embodiments may be of at least500 Daltons, and in other embodiments, specifically of at least 2000Daltons. In some embodiments the weight of the crystallizable sectionforms at least 20%, in other embodiments at least 50%, and in otherembodiments at least 70% of the total weight of the fpPCM. Mol. wts. canrange from 500 Daltons to millions of Daltons, as exemplified by the useof ultra-high mol. wt. polyethyelene (UHMWPE)

The molecular weight can be monodisperse or polydisperse where all thepolymer molecules are the same molecular weight or different molecularweights as defined by the polydispersity. Mn is the number averagemolecular wt., Mw is weight average molecular wt. and the molecular wt.polydispersity (Pd) is defined by Mn/Mw. A Pd of 1.0 means all polymermolecules are monodisperse and have the same molecular weight. Aspectsof a composition constructed in accordance with the present disclosurehave a Pd of between 1.0-100, in some embodiments between 1.0-10.0, andin yet other embodiments, between 1.0-5.0.

Aspects of the present disclosure pertain to utilizing a PCM with asingle phase change temperature or multiple such temperatures. Accordingto one embodiment, a fpPCM has at least one phase change temperature inthe range between −10° C. and 300° C. In other embodiments, the range isbetween 10° C. and 100° C. In these embodiments, the fpPCM may have aphase change enthalpy of at least 25 J/g. According to anotherembodiment, an fpPCM has a transition temperature in the range of 0° C.to 100° C., and in other embodiments, specifically between 40° C.−80° C.According to another embodiment, an fpPCM has a transition temperaturebetween −60° C. and 60° C. In some instances, a phase change materialcan have a latent heat that is at least about 1 Joule per gram, at leastabout 5 Joules per gram (J/g), at least about 10 J/g, at least about 20J/g, at least about 30 J/g, at least about 40 J/g, at least about 50J/g, at least about 60 J/g, at least about 70 J/g, at least about 80J/g, at least about 90 J/g, or at least about 100 J/g. Thus, forexample, the phase change material can have a latent heat from about 5J/g to about 400 J/g, 10 J/g to about 100, J/g, 20 J/g to about 100 J/g,from about 60 J/g to about 400 J/g, from about 80 J/g to about 400 J/g,or from about 100 J/g to about 400 J/g.

The phase change at each of the temperatures has its own enthalpy, sothat according to some of the embodiments, the composition used has asingle phase change enthalpy and, according to other embodiments,multiple such enthalpies. As used herein, the term “overall phase changeenthalpy” refers to the enthalpy of phase change in the case of astructure with a single phase change temperature and to the combinedenthalpies in case of multiple phase change temperatures. According toan embodiment of the disclosure, the composition has an overall phasechange enthalpy of at least 2.0 Joules/gram (J/g).

An fpPCM used in accordance with various aspects of the presentdisclosure can have a designed stereospecificty. The fpPCM can beatactic, isotactic or syndiotactic. The fpPCM can be L-, D- or Meso-.

According to an embodiment of the disclosure, the fpPCM may havehydrophilic side chains. According to the same or another embodiment ofthe disclosure the fpPCM may have hydrophobic side chains. Examples ofside chains or monomers which can provide these side chains are in thetable below.

Long Chain Group Containing Monomers R = Monomers Long chain n-CH₂═CR′CO₂(CH₂)_(n)CH₃ R′ = CH₃ or H, n = 10-25 alkyl Long chain n-alkylacrylates or methacrylates such as stearyl acrylate or crystalliziblestearyl methacrylate, segments CH₂═CH—O—(CH₂)_(n)CH₃, n = 10-25 Longchain n-alkyl vinyl ethers such as stearyl vinyl ether,CH₂═CH—O—CO—(CH₂)_(n)CH₃, n = 10-25, Long chain n-alkyl vinyl esterssuch as vinyl stearate, CH₂═C—CO—(CH₂)_(n)CH₃, n = 10-25, Long chainn-alkyl vinyl ketoness, CH₂═CH—(CH₂)_(n)CH₃, n = 4-25 Long chain n-alkylolefins such as undecene, or any other long chain n-alkyl containingunsaturated polymerizable monomer Long chain CH₂═CR′CO₂(CH₂CH₂O)_(n)OXR′ = CH₃ or H, n = 1-1,000, X = CH₃ or H crystallizible Glycol basedacrylates or methacrylates such as polyethyleneglycol glycolmethacrylate, polyethyleneglycol acrylate, segmentsCH₂═CH—(CH₂)_(m)—O—((CH₂)_(n)O)_(z)OX m = 0-4, n = 1-10, z = 1-1000, X =CH₃ or H Glycol based vinyl ethers such as polyethyleneglycol monovinylether CH₂═CH—O—CO—((CH₂)_(n)O)_(z)OX n = 1-10, z = 1-1000, X = CH₃ or Hglycol based vinyl esters such as polyethyleneglycol monovinyl ester orany unsaturated polymerizable hydroxyl functional monomer

In addition other crystallizable sections of pPCMs are contemplated,including radicals of fatty acids, radicals of long-chain dicarboxylicacids, radicals of fatty alcohols, radicals of dialcohols,polyester-polycarboxylic or as previously described.

While each of the fpPCM molecules carries at least one reactivefunction, large fpPCM molecules may carry multiple reactive functions.According to an embodiment an fpPCM carries at least one reactivefunction per 1,000,000 Daltons of the molecular weight and in someembodiments, two reactive functions.

In various embodiments, the functions are shown along the backbone, butthat is only one option. As indicated above, the functions could also beplaced at the end(s) of the backbone, on the side chains and anycombination of those. Each fpPCM may have a single or multiple reactivefunctions. fpPCM may also carry multiple reactive functions of a similarchemical nature or a combination of reactive functions of differentchemical nature.

As indicated, the reactive function of the fpPCM should be capable offorming covalent or electrovalent bonds with various substrates that mayform outer surfaces electrochemical devices. Substrates can includematerials that comprise a battery or other electrochemical devicesurface, casing, box, container, or package. Examples of reactivefunctions capable of forming covalent bonds are acid anhydride groups,amino groups, N-substituted amino groups and their salts, amide groups,imine groups, imide groups, azide groups, azo groups, amine-formaldehydegroups, carbonyl groups, carboxy groups and their salts, cyclohexylepoxy groups, epoxy groups, glycidyl groups, hydroxy groups, isocyanategroups, cyanate groups urea groups, aldehyde groups, ketone groups,ester groups, ether groups, alkenyl groups, alkynyl groups, thiolgroups, disulfide groups, silyl or silane groups, halogenated leavinggroups, peroxide groups, salt groups, groups based on glyoxals, groupsbased on aziridines, groups based on active methylene compounds or otherb-dicarbonyl compounds (e.g., 2,4-pentandione, malonic acid,acetylacetone, ethylacetone acetate, malonamide, acetoacetamide and itsmethyl analogues, ethyl acetoacetate, and isopropyl acetoacetate), halogroups, hydrides, or other polar or H bonding groups and combinationsthereof. fpPCMs capable of forming covalent bonds are disclosed incommonly assigned U.S. Pat. No. 8,404,341, the teaching of which isincorporated herein by reference in its entirety. Examples of reactivefunctions capable of forming electrovalent bonds are acid functions,basic functions, positively charged complexes and negatively chargedcomplexes. fpPCM capable of forming electrovalent bonds such asdisclosed in commonly assigned U.S. Pat. No. 8,221,910, the teaching ofwhich is incorporated herein by reference in its entirety. For example,the following are examples of suitable reactive functional groups:

According to one embodiment, the fpPCM may carry reactive functions asits end group or groups. Examples of such FP-PCMs are α,ω-diglycidylpolyesters, α,ω-diglycidyl ethers, α,ω-diisocyanates, α,ω-diureas,α,ω-dialkenes, α-glycidyl polyesters, α-glycidyl ethers, α-ureas andα-isocyanates. (See e.g. the structures depicted in FIGS. 7-10)

Hydrocarbons—Functional groups that vary based upon the number and orderof π bonds impart different chemistry and polarity. Each listing belowcontains C—H bonds, but each one differs in type (and scope) ofreactivity.

Chemical class Group Formula Structural Formula Alkene Alkenyl R₂C═CR₂

Alkyne Alkynyl RC≡CR′ R—≡—R′ Benzene derivative Phenyl RC₆H₅RPh

Toluene derivative Benzyl RCH₂C₆H₅RBn

Groups containing halogens—Haloalkanes are a class of molecule that isdefined by a carbon-halogen bond. This bond can be relatively weak (inthe case of an iodoalkane) or quite stable (as in the case of afluoroalkane). In general, with the exception of fluorinated compounds,haloalkanes readily undergo nucleophilic substitution reactions orelimination reactions. The substitution on the carbon, the acidity of anadjacent proton, the solvent conditions, etc. all can influence theoutcome of the reactivity.

Chemical class Group Formula Structural Formula haloalkane halo RX R—Xfluoroalkane fluoro RF R—F chloroalkane chloro RCl R—Cl bromoalkanebromo RBr R—Br iodoalkane iodo RI R—I

Groups containing oxygen—Compounds that contain C—O bonds each possessdiffering reactivity based upon the location and hybridization of theC—O bond, owing to the electron-withdrawing effect of sp² hybridizedoxygen and the donating effects of sp³ hybridized oxygen.

Chemical class Group Formula Structural Formula Acyl halide HaloformylRCOX

Alcohol Hydroxyl ROH

Ketone Carbonyl RCOR′

Aldehyde Aldehyde RCHO

Carbonate Carbonate ester ROCOOR

Carboxylate Carboxylate RCOO⁻

Carboxylic acid Carboxyl RCOOH

Ether Ether ROR′

Ester Ester RCOOR′

Hydro- peroxide Hydro- peroxy ROOH

Peroxide Peroxy ROOR

Groups containing nitrogen—Compounds that contain Nitrogen in thiscategory may contain C—O bonds, such as amides.

Structural Chemical class Group Formula Formula Amide Carboxamide RCONR₂

Amines Primary amine RNH₂

Secondary amine R₂NH

Tertiary amine R₃N

4° ammonium ion R₄N⁺

Imine Primary ketimine RC(═NH)R′

Secondary ketimine RC(═NR)R′

Primary aldimine RC(═NH)H

Secondary aldimine RC(═NR′)H

Imide Imide RC(═O)NC(═O)R′

Azide Azide RN₃

Azo compound Azo (Diimide) RN₂R′

Cyanates Cyanate ROCN

Isocyanide RNC

Isocyanates Isocyanate RNCO

Isothiocyanate RNCS

Nitrate Nitrate RONO₂

Nitrile Nitrile RCN R—≡N Nitrite Nitrosooxy RONO

Nitro compound Nitro RNO₂

Nitroso compound Nitroso RNO

Pyridine derivative Pyridyl RC₅H₄N

Groups containing phosphorus and sulfur—Compounds that contain sulfurand phosphorus exhibit unique chemistry due to their varying polarityand ability to form more bonds than nitrogen and oxygen, their lighteranalogues on the periodic table.

Structural Chemical class Group Formula Formula Phosphine Phosphino R₃P

Phosphodiester Phosphate HOPO(OR)₂

Phosphonic acid Phosphono RP(═O)(OH)₂

Phosphate Phosphate ROP(═O)(OH)₂

Sulfide or thioether RSR′

Sulfone Sulfonyl RSO₂R′

Sulfonic acid Sulfo RSO₃H

Sulfoxide Sulfinyl RSOR′

Thiol Sulfhydryl RSH

Thiocyanate Thiocyanate RSCN

Disulfide Disulfide RSSR′

Other chemical classes include Organosilanes, Siloxides, Silyl halides,Silyl hydrides, Hydrosilylation, Silenes, Siloles, and Hypercoordinatedsilicon.

According to another embodiment, the functional polymeric phase changematerial may also be chemically bound to the substrate. Binding may beone of covalent binding, electrovalent binding, direct binding, orbinding via a connecting compound. According to another embodiment,binding is such as the one resulting from a reaction between a reactivefunction of the fpPCM and a reactive function of the substrate,preferably the binding is a result of such reaction. The substrate canbe selected from the group consisting of plastic or polymeric layerssuch as plastic films, plastic sheets, laminates or combinations ofabove, metals, composites, other polymers, carbons, ceramics, glass,fiberglass or other known materials used in the construction of outersurfaces of electrochemical devices and containers for such devices.Examples of such outer surfaces include battery and electrochemical cellwalls, casings, covers, boxes, protective layers, containers, andpackages.

The fpPCM can be implemented as a coating, laminate, infusion, treatmentor ingredient in a coating, laminate, infusion, treatment that is formedadjacent to, on or within the substrate using any suitable coating,laminating, infusion, etc. technique. During use, the fpPCM can bepositioned so that it is adjacent to the outer surface of anelectrochemical device, thus serving as an inner coating. It is alsocontemplated that the fpPCM can be positioned so that it is exposed toan outside environment, thus serving as an outer coating. The fpPCMcovers at least a portion of the substrate. Depending on characteristicsof the substrate or a specific coating technique that is used, the fpPCMcan penetrate below the top surface and permeate at least a portion ofthe substrate. While two layers are described, it is contemplated thatthe article can include more or less layers for other implementations.In particular, it is contemplated that a third layer can be included soas to cover at least a portion of a bottom surface of the substrate.Such a third layer can be implemented in a similar fashion as the fpPCMor can be implemented in another fashion to provide differentfunctionality, such as water repellency, stain resistance, stiffness,impact resistance, etc.

In one embodiment, the fpPCM may be blended with a binder which may alsocontain a set of microcapsules that are dispersed in the binder. Thebinder can be any suitable material that serves as a matrix within whichthe fpPCM and possibly also the microcapsules are dispersed, thusoffering a degree of protection to the fpPCM and microcapsules againstambient or processing conditions or against abrasion or wear during use.For example, the binder can be a polymer or any other suitable mediumused in certain coating, laminating, or adhesion techniques. For certainimplementations, the binder may be a polymer having a glass transitiontemperature ranging from about −110° C. to about 100° C., and in someembodiments specifically from about −110° C. to about 40° C. While apolymer that is water soluble or water dispersible can be advantageous,a polymer that is water insoluble or slightly water soluble can also beused as the binder for certain implementations.

The selection of the binder can be dependent upon variousconsiderations, such as its affinity for the fpPCM, PCM and/ormicrocapsules or the substrate, its ability to modify heat transfer, itsbreathability, its flexibility, its elasticity, its softness, its waterabsorbency, its coating-forming ability, its resistance to degradationunder ambient or processing conditions, and its mechanical strength. Forexample, the selection of a binder can influence the hardness,stiffness, break elongation, and flex modulus of the TMM structure(e.g., the sleeve or the wrapped tape). As discussed previously, it maybe desirable in certain embodiments that a sleeve structure have a ShoreA hardness of >85 and a Shore D hardness of >25 (per ASTM D2240).Additionally, it may be desirable that a sleeve structure have a FlexModulus of >15 psi (per ASTM D790) and a break elongation of >20% (perASTM D638). The selection of a binder may be one way to achieve theseproperties. In particular, for certain implementations, the binder canbe selected so as to include a set of functional groups, acid anhydridegroups, amino groups, N-substituted amino groups and their salts, amidegroups, imine groups, imide groups, azide groups, azo groups,amine-formaldehyde groups, carbonyl groups, carboxy groups and theirsalts, cyclohexyl epoxy groups, epoxy groups, glycidyl groups, hydroxygroups, isocyanate groups, cyanate groups urea groups, aldehyde groups,ketone groups, ester groups, ether groups, alkenyl groups, alkynylgroups, thiol groups, disulfide groups, silyl or silane groups,halogenated leaving groups, peroxide groups, salt groups, groups basedon glyoxals, groups based on aziridines, groups based on activemethylene compounds or other b-dicarbonyl compounds (e.g.,2,4-pentandione, malonic acid, acetylacetone, ethylacetone acetate,malonamide, acetoacetamide and its methyl analogues, ethyl acetoacetate,and isopropyl acetoacetate), halo groups, hydrides, or other polar or Hbonding groups and combinations thereof.

These functional groups can allow chemical bonding to a complementaryset of functional groups included in either of, or any of, the fpPCM,the PCM, the thermal conductive particles, the microcapsules and thesubstrate, thereby enhancing durability of the article during processingor during use. Thus, for example, the binder can be a polymer thatincludes a set of epoxy groups, which can chemically bond to a set ofcarboxy groups included in the fpPCM, PCM, the thermal conductiveparticles, and/or the microcapsules. As another example, the binder canbe a polymer that includes a set of isocyanate groups or a set of aminogroups, which can chemically bond with those carboxy groups included inthe fpPCM, PCM, the thermal conductive particles, microcapsules, orsubstrate.

In some instances, a set of catalysts can be added when forming thecoating composition. Such catalysts can facilitate chemical bondingbetween complementary functional groups, such as between those includedin the binder and those included in the microcapsules. Examples ofmaterials that can be used as catalysts include boron salts,hypophosphite salts (e.g., ammonium hypophosphite and sodiumhypophosphite), phosphate salts, tin salts (e.g., salts of Sn⁺² or Sn⁺⁴,such as dibutyl tin dilaurate and dibutyl tin diacetate), and zinc salts(e.g., salts of Zn⁺²). A desirable amount of a tin salt or a zinc saltthat is added to the coating composition can range from about 0.001 toabout 1.0 percent by dry weight, such as from about 0.01 to about 0.1percent by dry weight. A desirable amount of a boron salt or a phosphatesalt that is added to the coating composition can range from about 0.1to about 5 percent by dry weight, such as from about 1 to about 3percent by dry weight. Other examples of materials that can be used ascatalysts include alkylated metals, metal salts, metal halides, andmetal oxides, where suitable metals include Li, Be, Na, Mg, K, Ca, Rb,Sr, Ti, V, Mn, Fe, Co Ni, Cu Zn Ga, Ge As, Se, Al, Y, Zr, Nb, Mo, Ru,Rh, Pd, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, La, Hf, Ta, W, Re, Os, Jr, Pt,Au, Hg, Tl, Pb, Bi, Po, A Ra, Ac, Ce, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho,Er, Tm, Yb, Lu, Th, Pa, U, Pu, etc. These metals and their compounds canbe used singly or blended. Organic acids and bases, such as those basedon sulfur (e.g., sulfuric), nitrogen (e.g., nitric), phosphorous (e.g.,phosphoric), or halides (e.g., F, Cl, Br, and I), can also be used ascatalyst. Further examples of materials that can be used as catalystsinclude acids such as citric acid, itaconic acid, lactic acid, fumaricacid, and formic acid.

Bonds between substrate, functional phase change material, binder, PCM,the thermal conductive particles, and/or microcapsules are, according tovarious embodiments, covalent, electrovalent or various combinations ofthose. Binding could be direct or indirect, e.g. via a connectingcompound. According to some embodiments, the connecting compound isselected from a group consisting of functional polymeric phase changematerial and microcapsules. According to another or the same embodiment,the functional polymeric phase change material may form a binder for atleast a portion of a second PCM.

According to another embodiment, the reactive function of the fpPCM canbe converted into another reactive function, which is more suitable forreacting with particular substrates.

According to another embodiment, the reactive function of the fpPCMcould be of various chemical nature. For example, reactive functionscapable of reacting and forming covalent or electrovalent bonds withreactive functions of various substrates, e.g. metals, plastics,components of an external wall of an electrochemical cell, externalcomponents of an electrochemical pack, and thermal interface materials.

According to another embodiment of the disclosure, the reactive functioncan be any of the following: 1) glycidyl or epoxy such as from glycidylmethacrylate or glycidyl vinyl ether; 2) anhydride such as from maleicanhydride or itaconic anhydride; 3) isocyanate such as from isocyanatomethacrylate, TMI® from Cytec Ind. or blocked isocyanates such as2-(0-[1′-methylproplyideneamino]carboxyamino)ethyl methacrylate; 4)amino or amine-formaldehyde such as from N-methylolacrylamide; and 5)silane such as from methacryloxypropyltriethoxysilane. Such reactivefunctions can react with OH functional groups of cellulosic basedmaterials; with hydroxyl or carboxyl groups of polyester based materialsand with amide functional groups of nylon functional resins.

According to still another embodiment of the disclosure, the reactivefunction may be a double bond, capable of binding to another doublebond, providing a cross-linking point, a polymerization point, etc. Theabove described reactions, linking or crosslinking reactions can betriggered by any energy such as light, UV, IR, heat, thermal, plasma,sound, microwave, radiowave, pressure, x-ray, gamma, or any form ofradiation or energy. They can be triggered by chemical reactions such asby the use of free radical, anionic or cationic catalysts or initiators.

The reactive function of the fpPCM can assume a positive charge and bindelectrovalently with a negative charge on the substrate. According toanother embodiment, the reactive function can assume a negative chargeand bind electrovalently with a positive charge on the substrate.According to another embodiment, the reactive functions of both thesubstrate and the fpPCM and/or microcapsule may be negatively chargedand binding is via a multivalent cation, which acts as a cross-linker.According to still another embodiment, the reactive functions of boththe substrate and the fpPCM and/or microcapsule may be positivelycharged and binding is via a multivalent anion, which acts as across-linker. The cross-linking multivalent cation, anion or both couldbe organic or inorganic.

Use of Crosslinked Polyether Polyol as PCM Casing

In addition to embodiments comprising a PCM of one composition and a TMMof a different composition, this disclosure also provides embodiments ofa sleeve or casing comprising a uniform, substantially homogenouspolymeric composition of a crosslinked polyether polyol throughout theentirety of the sleeve or casing structure. These crosslinked polyetherpolyols may comprise polyethylene glycols (PEG) or polyethylene oxides(PEO) to form shape-stable, moldable, and machinable casings with latentheat storage properties and fire resistant properties. It is known inthe art that PEO are essentially very high mol. wt. versions of PEG, andthat both polymers have the same chemistry. In general, PEG refers tooligomers and polymers with a molecular mass of less than 20,000 g/mol,and PEO refers to oligomers and polymers with a molecular mass of over20,000 g/mol. Throughout this disclosure, embodiments that refer toeither a PEG or PEO alone may be understood to include both (or either)PEGs and PEOs, unless otherwise specified. As known in the art, a polyolrefers to a compound with multiple hydroxyl groups available forreactions. PEGs and PEOs are among these polyols (preferably, they arediols, containing two hydroxyl groups) and are known as polyetherpolyols. Other polyols with more or fewer hydroxyl groups, and otherspecific types of polyether polyols, may also be utilized in variousembodiments without departing from the present disclosure.

Although PEGs and PEOs have been used as PCMs in the prior art, certainlimitations, such as susceptibility to thermal degradation, have limitedtheir use in certain applications, such as those requiring highertransition temperatures. However, when PEGs/PEOs have their chainsextended or are crosslinked, the system mol. wt. increases, which allowstheir transition temperatures to change in correlation with their mol.wt., crosslink density, additive type or amount, and other formulationvariables. A number of other advantages can also be achieved by chainextending and/or crosslinking throughout the disclosure, the terms chainextending and crosslinking may be used interchangeably, because bothtypes of reactions can be used to achieve the desired properties ofembodiments of the disclosure. PEG/PEO chains in accordance withembodiments of the present disclosure. For example, crosslinkedpolyether polyols, once cured, may form a shape-stable material that canwithstand machining and milling in order to form a custom-shaped casingsand housings for different configurations of electrochemical cells andpacks. For example, embodiments of the disclosure may be formed insubstantially rectangular housings or casing comprising a plurality ofopenings configured to retain electrochemical cells, as shown in FIG.4D.

Another benefit of utilizing crosslinked polyether polyols as a thermalmanagement material is that the shape of such crosslinked polyetherpolyol composites are stable enough to withstand the expansion andcontraction of electrochemical cells during their thermal cycling, andmay maintain close contact with the cells throughout the cycles evenwithout the incorporation of elastomeric materials as describedthroughout this disclosure. A further benefit is that the compositesthemselves can be used to form the entire housing or casing because theyare solid-solid PCMs, meaning they do not become liquid when melted, andtherefore do not leak. As a result, a separate housing or container isnot required; the cured crosslinked polyether polyol itself can be usedto form an entire casing. Throughout the disclosure, a casing comprisingunitary structure made out of a crosslinked polyether polyol may bealternatively referred to as a latent heat storage (LHS) casing. Thoughall the PCM materials described in the present disclosure is capable ofstoring latent heat, casings comprising crosslinked polyether polyolsmay be referred to as LHS casings to differentiate from embodiments ofthe disclosure comprising multiple types of polymeric PCM and TMMmaterials.

Yet another benefit of crosslinked polyether polyol composites aselectrochemical cell casings is that the composites may be inherentlyfire-retardant; in some embodiments, the fire-retardant properties arehigh enough to pass the UL-94 (Standard for Tests for Flammability ofPlastic Materials for Parts in Devices and Appliances,http://ulstandards.ul.com/standard/?id=94_6, UL LLC) flammability testwith a rating of V0. In some embodiments, this fire-retardant rating maybe achieved even without the use of any fire retardant additives of thetype described throughout this disclosure. In other embodiments,composites may achieve ratings of V1 or V2 without the addition offire-retardant additives. In yet other embodiments, fire-retardantadditives may be added to improve the flame resistance that thecomposites could otherwise achieve.

Because many of the embodiments of crosslinked polyether polyol casingsare fire-resistant PCMs, another benefit they provide is the preventionof thermal runaway of electrochemical cell packs. In one aspect, the PCMproperties of the casings themselves cool the electrochemical cells toprevent individual cells from overheating to the point of combustionthemselves. However, as described earlier in this disclosure, sometimesuncontrollable factors, such as manufacturing defects or puncturing, cancause the thermal runaway of one electrochemical cell despite goodthermal management. In such cases, the flame-resistance of the casingitself can prevent the thermal runaway from spreading to otherelectrochemical cells. For example, in order to meet the UL-94 ratingstandard of V0, a material must not have flaming combustion for morethan ten seconds, or glowing combustion for more than 30 seconds, evenwhen a flame is applied directly to the material for a certain period oftime. As a result of being flame resistant to at least this degree,materials of the present disclosure can, in many cases, be exposed to acombusting electrochemical cell until all the materials of the cell havebeen fully exhausted. The casing materials may be exposed withoutcatching fire themselves, all the while insulating other cells againstthe heat, thereby effectively extinguishing a combusting cell.

Yet another benefit of using the casings comprised of crosslinkedpolyether polyols is that the temperature management properties can helpelectrochemical cells charge faster than they otherwise could be withouttemperature management materials. Many applications of electrochemicalcells (such as mobile device batteries and automobile batteries) nowrequire faster charging due to demands by manufacturers and consumers.However, faster charging typically results in higher temperatures andpotential overheating. Because casings of the present disclosure cankeep temperatures of electrochemical cells cool despite fast charging,applications can achieve faster charging for longer periods of timewhile keeping the cells cool. This cooling minimizes the risk ofoverheating and enables faster charging when a cell is retained in acasing of the present disclosure than when a cell is not retained in anytemperature management material.

Various chain extenders may be reacted with the polyether polyols inorder to achieve the crosslinking, which allows for adjustment of thechain length, and therefore the mol. wt. of the polyether polyols. Inmany embodiments, types of isocyanates may be used as crosslinkers orchain extenders. In particular, certain embodiments utilizediisocyanates such as hexamethylene diisocyanate (HDI) and4,4′-diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI),methylene dicyclohexyl diisocyanate or hydrogenated MDI (HMDI), orisophorone diisocyanate (IPDI), depicted below:

As shown in the above molecular diagrams, all isocyanates have an R—NCOreactive group, and diisocyanates have two R-NCO groups. Throughoutseveral of the following tables and charts, isocyanates anddiisocyanates may be abbreviated simply as “NCO.” In general, thecombination of a diisocyanate and a polyether polyol, in the presence ofa reactant, will combine to extend the chain of the polyether polyol asdepicted below:

The extent to which the chains of the PEG or PEO will be extended and/orcrosslinked in various embodiments is dependent on several factors,including what kind of diisocyanate is used and in what ratios thediisocyanate and PEG/PEO are combined. In various embodiments, the ratioof diisocyanate to polyether polyol may be between 0.5:1 and 1.5:1. Thevarious ratios also affect the viscosity, crystallinity, melting points,and latent heat of the resulting composites. The multiple examples ofembodiments of the present disclosure listed in the tables belowdemonstrate the relationships between the diisocyanate/polyether polyolcombinations, their ratios, and the resulting physical properties of thecomposites.

In addition to utilizing diisocyanates as primary crosslinkers and chainextenders of the polyether polyols, other branching agents and chainextenders may also be reacted with the composite. Some are themselvespolyol blends. These may include butanediol (BDO), polytetramethyleneglycol (PTMG), and various types of polyetheramines. One suchpolyetheramine used in the experiments listed in the tables belowincludes bis(3-aminopropyl)polyethylene glycol with a mol. wt. of 1500(known commercially as NPEG1500), but other types of polyetheramines mayalso be used. Other branching agents and chain extenders that may beused include, but are not limited to, Jeffamines® from HuntsmanInternational LLC. Alternatively, isocyanate prepolymers, such as thoseknown commercially as Bayhydur® and Desmodur® from Covestro AG, andSilmer NCO from Siltech Corp. may also be used. These branching agentsand chain extenders can be used in a number of combinations and ratiosto achieve precise control of the polyether polyol.

In some embodiments of the crosslinked polyether polyol composite, arelatively low mol. wt. PEG may be combined with a dianhydride in orderto achieve crosslinking and changes in melting point and latent heat.Examples of dianhydrides reacted with PEGs, and their respectivephysical properties, are depicted in Table 4 below. It is contemplatedthat the following dianhydrides, as well as others, may be used inPEG/dianhydride embodiments of the present disclosure:

Dianhydrides

Benzene-1,2,4,5-tetracarboxylic dianhydride, PMDA, Pyromelliticdianhydride

N,N-Bis[2-(2,6-dioxomorpholino)ethyl]glycine, DTPA dianhydride,Diethylenetriaminepentaacetic dianhydride

1,4,5,8-Naphthalenetetracarboxylic dianhydride, NTCDA

4,4′-Ethylenebis(2,6-morpholinedione), EDTA dianhydride,Ethylenediaminetetraacetic dianhydride

1,2,3,4-Cyclobutanetetracarboxylic dianhydride,Cyclobutanetetracarboxylic acid dianhydride, Cyclobutanetetracarboxylicdianhydride, Maleic anhydride cyclic dimer

4,4′-Carbonyldiphthalic anhydride,Benzophenone-3,3′,4,4′-tetracarboxylic dianhydride

3,3′,4,4′-Biphenyltetracarboxylic dianhydride

PTCDA, Pigment Red 224, Perylene-3,4,9,10-tetracarboxylic dianhydride

Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride

cis-1,2,3,4-Cyclopentanetetracarboxylic dianhydride, or otherstereoisomer

Tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride

Meso-Butane-1,2,3,4-tetracarboxylic dianhydride, or other isomers

3,3′,4,4′-Diphenylsulfonetetracarboxylic dianhydride

2,2′-Bis-(3,4-Dicarboxyphenyl) hexafluoropropane dianhydride, 6FDA

HQDA; HYDROQUINONE DIPHTHALIC ANHYDRIDE; 4,4′-(p-Phenylenedioxy)bis[phthalic anhydride];4,4′-(4,1-Phenylenedioxy)bis[phthalic anhydride];1,4-Bis(3,4-dicarboxyphenoxy)benzene dianhydride; 1,4-Bis(3,4-dicarboxyphenoxy)benzene dianhydride(HQDPA); 1,4-Diphenoxybenzene-3′,4′,3″,4″-tetracarboxylic acid anhydride

2,3,3′,4′-Diphenyl ether tetracarboxylic acid dianhydride

In addition to any of the above-mentioned combinations of polyols andcrosslinkers, chain extenders, and/or branching agents, compositepolymers of the present disclosure may also contain various types andconcentrations of thermal conductivity additives. Though the crosslinkedpolyether polyols themselves already possess good thermal conductivityproperties (given the properties of such phase change materials), theaddition of particular thermally conductive materials can enhance suchproperties even further. Examples of thermal conductivity additives thatmay be used with crosslinked polyether polyol composites of the presentdisclosure include natural graphite, vein graphite, amorphous graphite,flake graphite, expandable flake graphite, synthetic graphite, surfaceenhanced graphite (SEFG), nano graphite, graphene, cokes, carbon,activated carbon, carbon black, surface modified graphite/graphene(wherein the surface contains oxides, hydroxyls, carboxyls, and amines),ceramics (e.g., boron nitride, aluminum nitride, etc.), and metal flakes(e.g., aluminum, copper, etc.)

The following tables show numerous embodiment combinations ofcrosslinked polyether polyols that were combined in experiments andmeasured to determine their physical properties. The tables are dividedinto different types of combinations of polyether polyols, crosslinkers,chain extenders, branching agents, and additives in order to illustraterelationships between combinations of reactants and the resultingphysical properties of their composites.

In order to determine the effects of the various reactants on thephysical properties of each of these experimental composite materials,the same procedures were used to create the composites and then tomeasure them. Each composite material was created using a batchpolymerization process. All blending and reactions were done under a dryN₂ atmosphere. Alcohols or amines were blended and melted, and thenisocyanate or anhydride reactants were added and mixed. The vessels inwhich the reactants were mixed were then sealed and held at atemperature of approximately 70° C. The composites were then let to cooland then visually inspected.

In order to measure the transition temperatures and latent heat of eachcomposite material, a differential scanning calorimeter was used. Eachcomposite sample, once prepared as described above, was held in ahermetically sealed aluminum sample pan. The testing was conducted undera constant N₂ flow. First, the samples were cooled to −10° C., and thenisothermally held at that temperature for four minutes. Then, thesamples were heated from −10° C. to 80° C. at 5° C. per minute. Then thesamples were isothermally held at 80° C. for one minute. Next, thesamples were cooled from 80° C. to −10° C. at 5° C. per min. This cycleof cooling and heating was repeated twice for each sample. Data from thesecond melt peak and the second crystallization peak were recorded foreach sample.

Thermal conductivity properties of each sample were also measured usinga thermal conductivity sensor known as a C-Therm TCi analyzer fromC-Therm Technologies Ltd. Sample disc were made that were 1-2 mm biggerthan the sensor and a minimum of 5 mm thick. A small amount of thermalgrease was applied to the sensor to provide a consistent and completeinterface with the surface of the sample discs. The sample was runeither using a setting known as the C-Therm “ceramics” internal testmethod if the material was anticipated to have conductivity of >1.1W/m·K, or using a setting known as the C-Therm “polymers” internal lestmethod if the material was anticipated to have conductivity of <1.1W/m·K. Sample disc were made that were 1-2 mm bigger than the sensor anda minimum of 5 mm thick. A small amount of thermal grease was applied tothe sensor to provide a consistent and complete interface with thesurface of the sample discs. Each sample was tested ten times, and theaverage measurement of the tests is listed in each table.

Though numerous experimental combinations of composites according to thedisclosure are shown in the tables below, these are only a few of themany possible combinations. This disclosure contemplates any kind ofpolyether polyol that is crosslinked, chain extended, and/or branched inorder to achieve the thermal management benefits described herein. Thisdisclosure should not be construed to be limited to the examples listedbelow.

TABLE 1 PROPERTIES OF DIISOCYANATE AND POLYOL TYPE COMPOSITES AND EFFECTOF REACTANT RATIO Exp.# 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 PEG1000 X X X X X PEG 6000 X X X X X PEG 10K X X X X X Terathane ® X X 1800PTMG HMDI X X X X X MDI X X X IPDI X X X TDI X X X NCO:OH 0:1 1:1 1:11:1 1:1 0:1 1:1 1:1 1:1 1:1 0:1 1:1 1:1 1:1 1:1 1:2 1:1.3 Ratio Melt Pk32 28 26 23 27 57 60 58 57 57 60 58 58 59 57 27 27 (2nd) Melt J/g 153109 99 93 70 176 176 169 166 161 179 171 170 169 162 78 39 (2nd) Cryst.pk 31 26 24 20 4 47 47 45 41 41 50 49 48 47 46 6 1 Cryst. J/g 155 113105 92 66 177 177 170 165 164 184 173 170 168 162 74 46 UL94 FR V0 V0 V0V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 Fail Fail

Table 1, shown above, shows various combinations of relatively low torelatively high mol. wt. PEGs (rows 1-4; PEG 1000, PEG 6000, PEG10K, andTerathane® 1800 PTMG) each combined solely with one type of diisocyanate(rows 6-10; HMDI, MDI, IPDI, TDI). Each type of the first three PEGs wasmeasured as a control without being reacted with a diisocyanate (Cols.1, 6, and 11). Then, each PEG was reacted with a different diisocyanate.Each reaction had a ratio of polyol to diisocyanate of 1:1. As seen, thetransition temperatures and latent heats of the composites differ fromthose of the polyols alone, and the different types of diisocyanatesused result in differing physical properties. Notably, the PEG materialsby themselves, and each of the combinations of PEG and diisocyanates ina 1:1 ratio resulted in a fire retardancy rating of V0. However, thecombinations of HDMI and Terathane® in ratios of 1:2 and 1:1.3, whichresulted in significantly lower melting points and latent heats, alsoresulted in failing fire-retardancy tests. The above table shows how thetype of diisocyanates and the ratios of the reactants can both be usedto adjust to desired physical properties.

TABLE 2 PROPERTIES OF ISOCYANATE, ISOCYANATE TYPE, POLYOL TYPE, POLYOLCOMPOSITES AND EFFECTS OF REACTANT RATIO Exp.# 18 19 20 21 22 23 24 2526 27 28 29 30 PEG 2000 X X PEG 3000 X X X X X X X X PEG 6000 X X X BDOX X HMDI X X X MDI X X X X Desmodur DN X X Silmer NCO X C50 Silmer NCO XDi100 NCO:BDO:PEG 1.2:0:1 1.2:0:1 1.2:0:1 1.2:0:1 1.5:0:1 1.1:0:11.1:0:1 0:0:1 1:0:1 2:1:1 0:0:1 1:0:1 2:1:1 Ratio Melt Pk (2nd) 37.349.4 44.5 53.3 34.0 43.2 48.1 50.4 47.9 44.4 57.1 56.9 55.4 Melt J/g(2nd) 77 90 89 121 61 74 99 145 99 79 132 133 130 Cryst. pk 13.0 27.924.0 34.8 14.5 22.5 26.9 23.0 24.4 2.8 36.0 31.1 25.8 Cryst. J/g 77 9285 121 68 77 101 144 98 75 127 129 128

Table 2 shows a second set of experiments in which three different mol.wts. of PEG (rows 1-3; PEG 2000, PEG 3000, and PEG 6000) were combinedwith an aliphatic diol (row 4; butanediol BDO) and/or diisocyanate (rows5-6; HMDI and MDI) and/or multifunctional or branched isocyanatecrosslinkers/chain extenders (rows 7-9, Desmodur® DN, Silmer® NCO C50,Silmer® NCO Di100). As seen, varying the reactants and their ratiosallows for the adjustment of melting point, transition temperatures, andlatent heat capacities to suit particular applications.

TABLE 3 PROPERTIES OF DIISOCYANATE, POLYOL TYPE AS A RESULT OF REACTANTRATIO Exp.# 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 PEG X X X X1500 PEG X X X X 2000 PEG X X X X 3000 PEG X X X X 4000 HMDI X X X X X XX X MDI X X X X X X X X NCO:OH 1:1 1.25:1 1:1 1.25:1 1:1 1.25:1 1:11.25:1 1:1 1.25:1 1:1 1.25:1 1:1 1.25:1 1:1 1.25:1 Ratio Melt Pk 38.028.0 42.7 36.0 50.3 45.2 53.0 51.0 46.5 37.0 50.0 44.0 53.8 51.5 57.454.5 (2nd) Melt J/g 70 46 86 61 103 69 108 87 96 60 105 81 126 96 129105 (2nd) Cryst. −2.5 −6.0 19 5.0 28.6 21.9 31 30.8 26.5 15.0 29.5 25.035.0 32.5 37.0 36.0 pk Cryst. 70 22 90 84 110 92 119 111 99 68 107 93127 118 137 119 J/g UL94 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0 V0FR

Table 3 shows that transition temperatures and latent heat can beadjusted simply by using different ratios of particular polyols (rows1-4; PEG 1500, PEG 2000, PEG 3000, and PEG 4000) to particulardiisocyante crosslinkers/chain extenders (rows 6-7; HMDI and MDI). Asshown, each type of PEG in the experiment was reacted with each of twodiisocyanates, HMDI and MDI, but in ratios of 1:1 and 1.25:1. Ingeneral, when the ratio of PEG to diisocyanate was 1.25:1, the meltingpoints and latent heat capacities were lower than in the same reactantcombinations of ratios of 1:1. As in earlier experiments, eachcomposition achieved a fire resistance rating of V0.

TABLE 4 PROPERTIES OF DIANHYDRIDE, POLYOL TYPE, OR DIAMINE TYPECOMPOSITES Exp.# 47 48 49 50 51 52 53 PEG 400 X X PEG 1000 X X XNPEG1500 X X PMDA X X EDTA dianhydride X X Anhydride:OH or 0:1 1:1 0:11:1 1:1 0:1 1:1 Anhydride:NH Melt Pk (2nd) 8.5 1.2 44.2 32.7 34.2 52.240.6 Melt J/g (2nd) 110 2 139 25 89 159 61 Cryst. Pk −18.7 −25.6 23.75.4 18.8 21.2 17.6 Cryst. J/g 113 4 150 23 31 155 11

Table 4 shows the properties of composites in alternative embodiments ofthe disclosure; namely, amine or hydroxyl functional polyols (rows 1-3;PEG 400, PEG 1000, and NPEG 1500; NPEG 1500 is a diamine) can becrosslinked and/or chain extended with dianhydrides (rows 5-6, PDMA,EDTA dianhydride). As shown, the melting points and latent heat valuesof the crosslinked composites are all lower compared to their respectivepolyols alone. The results also show that slightly different physicalproperties of the PCM composites may be achieved by using differentdianhydride reactants.

TABLE 5 PROPERTIES OF DIISOCYANATE, POLYOL TYPE AND THERMAL CONDUCTIVITYADDITIVE COMPOSITES Exp.# 53 54 55 56 57 58 59 60 61 62 63 64 65 PEG6000 X X X X X X X X X X X X X MDI X X X X X X X X X X X X X Graphiteflake X X X Nano Graphite X X X Graphene X X SEFG X X Boron Nitride X XNCO:OH 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 Wt. %Additive 0 10 20 30 5 10 20 10 20 20 30 30 40 Melt Pk (2nd) 56.9 55.855.5 55.4 56.4 56.1 55.2 55.4 52.4 54.5 54.3 55.1 54.2 Melt J/g (2nd)133 121 105 85 135 126 95 125 101 107 91 89 78 Cryst. pk 31.1 29.8 29.930.5 31.0 30.9 30.8 30.1 29.5 29.1 28.9 29.5 29.5 Cryst. J/g 129 122 10490 133 126 91 122 105 107 92 92 75 Thermal 0.22 0.52 0.88 1.12 0.65 1.312.94 1.66 3.21 0.91 1.45 1.96 2.87 Conductivity (W/m · K)

Table 5 shows the resulting physical properties of crosslinked polyetherpolyols according to embodiments of the disclosure combined with varioustypes and concentrations of thermal conductivity additives. In theseexperiments, PEG 6000 was combined with MDI diisocyanate and severaltypes of thermal conductivity additives (rows 5-10; graphite flake, nanographite, graphene, surface enhanced graphite, and Boron Nitride). Thethermal conductivity additives generally increased thermal conductivityas measured by W/m·K, and generally, higher concentrations of aparticular additive in a composite increased the thermal conductivitycompared to lower concentrations of the same material. In several cases,(e.g., experiment numbers 56, 59, 60, 61, 64, and 65) the embodimentcomposites yielded greater than 1.5× improved thermal conductivity ascompared to the PEG/diisocyanate combinations alone.

TABLE 6 PROPERTIES OF DIISOCYANATE, POLYOL TYPE AND FR ADDITIVECOMPOSITES Exp.# 66 67 68 69 70 71 72 73 74 PEG 2000 X X X X X PEG 6000X X X X BDO X X X X X X MDI X X X X X X X Desmodur DN X X ExpandableGraphite X X Flake AP760 X X Firemaster2100R:ATO X X NCO:BDO:PEG Ratio1.2:0:1 1.2:0:1 2:1:1 2:1:1 2:1:1 2:1:1 2:1:1 2:1:1 0.6:0:1 Wt. %Additive 5 5 0 0 20 20 15 15 0 Melt Pk (2nd) 37.5 48.9 39.9 55.1 33.652.6 37.4 54.9 38.9 Melt J/g (2nd) 71 85 69 131 54 99 59 105 146 Cryst.pk 13.4 28.3 9.3 26.1 5.2 25.2 8.8 26.8 18.5 Cryst. J/g 71 88 71 119 55105 59 108 152 UL94 FR V1 V1 Fail Fail V0 V0 V1 V1 V0

Table 6 shows experiments in which one or more polyols (rows 1-3; PEG2000, PEG 6000, BDO) were reacted with various multifunctionalcrosslinkers (rows 5-9; MDI, Desmodur® DN. Some of the resultingcomposites were further combined with a fire retardant additive (rows11-13; expandable graphite flake, Exolit®AP760 Ammonium Polyphosphate,Firemaster® 2100R Decabromodiphenyl ethane:ATO (antimony trioxide)).These materials can be obtained from companies such as Clariant Inc.,Chemtura Corp., etc. As shown, certain crosslinked polyol compositesfailed a flammability test without any fire retardant additives(experiment numbers 68 and 69), but the same composites achieved a fireretardancy rating of V0 with the addition of a fire retardant additive(experiment numbers 70 and 71). The results show that various levels offire retardancy can sometimes be achieved by certain embodiments ofcrosslinked polyether polyol composites, but that those properties canbe further enhanced with the addition of fire retardant additives.

FIGS. 21-24 illustrate experiments conducted to measure both the thermalmanagement properties of electrochemical cell casings comprised of thecrosslinked polyether polyols of the present disclosure, as well as theperformance benefits of the electrochemical cells that were achieved byusing such a material for thermal management.

FIG. 21 is a diagram of four electrochemical cells, labeled 1, 2, 3, and4 disposed in a housing 2100, the housing being comprised of a compositepolymeric crosslinked polyether polyol according to the presentdisclosure. For the purposes of this disclosure, the terms “housing” and“casing” may be used interchangeably. The view 2100A on the left depictsa top view of the positive terminals of each electrochemical cell, andaccordingly, each cell is labeled 1+, 2+, 3+, and 4+. The view 2100B onthe right is a bottom view of the same electrochemical cells shown inthe left view, and depicts the negative terminals of the electrochemicalcells. Accordingly, each cell is labeled 1−, 2−, 3−, and 4−. In theexperiment to test the performance properties of the casing, the fourelectrochemical cells (which were 1.5 Ah Li-ion 18650 cells) wereconnected in parallel and connected to a battery tester. The testingprogram comprised the steps of resting the cells for one minute, thencharging them at 6A until the voltage reached 4.2V, then tricklecharging the cells until the current dropped to 0.25A. Then, the cellswere allowed to rest for 30 seconds, after which time the cells weredischarged at 80A until the voltage reached 2.5V. After that, the cellswere allowed to rest for ten minutes before restarting the charging stepof the cycle. This cycle of charge and discharge was repeated 1000times. In order to test the temperature the surface of the cells,thermocouples were placed at the locations shown in FIG. 21.Thermocouple location 2103 was near cell 1, thermocouple location 2107was near cell 2, and thermocouple location 2108 was near cell three.Though the depth of the thermocouple placement is not apparent from thediagram, the thermocouples were placed midway between the positive andnegative terminals of the cells.

In addition to the testing of the electrochemical cells contained withinthe housing, the same test was performed on a control cell that was notcovered by any casing at all. The following graphs compare themeasurements taken from the control cell and one or more of the cells(which may be referred to as “experimental cells”) housed in the casing2100.

FIG. 22 shows the outer surface temperatures reached by each of thecontrol cell (line 2201), experimental cell 1 (line 2203), experimentalcell 2 (line 2207), and experimental cell 3 (line 2208). As shown, thecell surface temperature for the control cell reached up to 65° C.,while the experimental cells only reached up to about 52° C.

Similarly, FIG. 23 shows the temperatures of the control cells and eachof the experimental cells over time. Table 2301 shows that the controlcell initially reached temperatures of approximately 65° C. and rose tonearly 70° C. over time. In contrast, experimental cells 1 and 2 shownin tables 2303 and 2307 only initially reached temperatures ofapproximately 50° C. and did not exceed 57° C.

As previously discussed with reference to Table 6 above, manyembodiments of composite polymeric casings of the present disclosure mayhave thermal conductivity additives that increase the thermalconductivity properties of the casings. FIG. 24 shows the results ofthermal modeling simulations performed to measure the thermalconductivity of one such embodiment containing one or more thermalconductivity additives described in this disclosure. For ease ofreference, this embodiment will be referred to as the “thermallyconductive housing” in describing the tests in FIG. 24. The thermallyconductive housing was compared to a different PCM-TMM embodiment of thepresent disclosure without thermal conductivity additive (a “PCM-TMMhousing”), and a plastic control housing with negligible thermalmanagement properties. In these tests, he computer simulation producedthe temperature of the three different housings at three differentlocations in the housings. The first graph 2401 shows the temperature ofthe center of the housings, with the plastic control housing reaching atemperature of over 380K, while the PCM-TMM housing without thermalconductivity additives reached a temperature of only 360K, and thethermally conductive housing reached less than 355K. It is contemplatedthat material at the center of any of the housings is likely to reachthe highest temperature of any other location in the housing because itis surrounded by cells from multiple directions.

The second graph 2402 of FIG. 24 shows that when measuring thetemperatures at the edges of the battery housings, the edges of thethermally conductive housing increased in temperature quickly andsharply as compared to the more gradual temperature increases of theedges of both the plastic control housing and the PCM-TMM housing. Thesecond graph 2402 illustrates that due to the thermal conductivityproperties of the thermally conductive housing, more heat can bedissipated and distributed throughout a greater quantity of the phasechange material. The fact that the temperature is higher at the edges ofthe thermally conductive housing indicates that temperatures at otherlocations of the thermally conductive housing are likely lower than theywould have been if heat had not been transferred so efficiently outtoward the edges of the housing.

The third graph 2403 of FIG. 24 shows that the thermally conductivehousing allows for highly effective utilization of the PCM's transitiontemperature even in a corner of a battery casing. As shown, thethermally conductive housing reaches its transition temperature morequickly than the PCM-TMM housing and remains there for a longer periodof time.

FIG. 25 shows a separate experiment testing the discharge capacityretention of an electrochemical cell batteries contained in a casingaccording to the present disclosure housing of as compared to anelectrochemical cell without a casing over the course of over 800cycles. As shown, the control cell, with its discharge capacity depictedby the line 2505, lost more discharge capacity as compared to theexperimental cells contained in the housing, depicted by the line 2510.After approximately 400 cycles, the control cell lost discharge capacityeven more significantly over time.

Any of the combinations of the polyols, crosslinkers, chain extenders,branching agents, catalysts, and or additives described in the tablesabove may be combined in the desired ratios in order to adjust theproperties of transition temperature, melting point, latent heat,thermal conductivity, and fire resistance required by a particularapplication.

In view of the above tables, graphs, and descriptions, embodiments ofthe present disclosure provide a composite polymeric material forelectrochemical cell management, the composite polymeric materialcomprising a crosslinked polyether polyol phase change material. In manyembodiments, the material may be configured to be in physical contactwith at least a portion of an electrochemical cell. The compositepolymeric material may also be formed into a casing for electrochemicalcells, the casing comprising a unitary structure comprised of asubstantially homogeneous crosslinked polyether polyol phase changematerial, the unitary structure having one or more openings configuresto retain the one or more electrochemical cells in thermal contact withthe crosslinked polyether polyol phase change material.

In some embodiments, the composite polymeric material may comprise oneof a crosslinking agent or a chain extending agent and a polyol in aratio of between approximately 0.5:1 and 1.5:1. In some embodiments, thepolyol may comprise either a linear or a branched polyol. Further, insome embodiments, the crosslinking agent or chain extending agent may bebranched or linear. Many embodiments of the composite polymeric materialmay have a transition temperature of between 25° C. and 140° C., and insome embodiments specifically between 45° C. and 60° C. The material mayhave a latent heat of greater than 2 Joules per gram, and in manyembodiments, specifically between 70 and 100 Joules per gram. Thevarious embodiments may comprise a solid-solid PCM and may bemachinable, moldable, and/or fire resistant. The casing comprising thecomposite polymeric material may, when used in conjunction with one ormore electrochemical cells during a plurality of charge and dischargecycles of the one or more electrochemical cells, extends the dischargecapacity life of the one or more electrochemical cells as compared tothe original discharge capacity life of the one or more electrochemicalcells.

In certain embodiments, the casing may comprise a thermal conductivityadditive. In such embodiments, the crosslinked polyether polyolcomprising the thermal conductivity additive may have a thermalconductivity of greater than 1.5 times the thermal conductivity of thecrosslinked polyether polyol alone. In some embodiments, in order tocreate the crosslinked polyether polyol, the polyol and the crosslinkingagent or branching agent may be reacted using a catalyst. Someembodiments may further comprise one or more of a water scavengeradditive, an antioxidant additive, or a fire-retardant, examples ofwhich are described throughout the disclosure.

Examples of fpPCM Structures

FIGS. 7-10D are schematic drawings of fpPCMs used in accordance withvarious aspects of the present disclosure. Both are composed of abackbone chain and side chains. The fpPCM in FIG. 7 represent long chainalkyl polyacrylate or polymethacrylate, and 7A-7C where 7A is long chainalkyl vinyl esters, 7B is long chain vinyl ethers and 7C is long chainalkyl olefins.

FIGS. 8A and 8B represent long chain glycol polyacrylates orpolymethacrylates, where 8A is long chain glycol vinyl esters and 8B islong chain glycol vinyl ethers.

In FIGS. 7 and 8, R represents one or more of the reactive functions(s)described above. In those figures, the functions are drawn along thebackbone, but that is only one option. As indicated above, the functionscould also be placed at the end(s) of the backbone, on the side chainsand any combination of those. Each fpPCM may have a single or multiplereactive functions. fpPCM may also carry multiple reactive functions ofa similar chemical nature or a combination of reactive functions ofdifferent chemical nature. The length of the side chains may vary indifferent embodiments as shown by the variable chain length n.

With reference to FIGS. 9A-9F, FIG. 9A drawing depicts an acidic or lowpH carboxyl functional FP-PCM ionically interacting with a basic or highpH amino functional substrate. FIG. 9B depicts basic or high pH aminofunctional fpPCM ionically interacting with an acidic or low pH carboxylfunctional substrate. FIG. 9C depicts basic or high pH amino functionalfpPCM and a basic or high pH amino functional substrate beingneutralized and ionically bound or “crosslinked” with an anion such asan amine. FIG. 9D depicts an acidic or low pH carboxyl functional fpPCMand an acidic or low pH carboxyl functional substrate being neutralizedand ionically bound or “crosslinked” with a cation such as a metal salt.FIG. 9E depicts basic or high pH amino functional fpPCM and a basic orhigh pH amino functional substrate being neutralized and ionically boundor “crosslinked” with negatively charged organic compound such asdicarboxy functional polymer or dicarboxy functional fpPCM. FIG. 9Fdepicts an acidic or low pH carboxyl functional fpPCM and an acidic orlow pH carboxyl functional substrate being neutralized and ionicallybound or “crosslinked” with positively charged organic compound such asdiamine functional polymer or diamine functional fpPCM.

With reference to FIGS. 10A-10D, FIG. 10A depicts a covalent ether bondfrom the reaction of an fpPCM epoxy and hydroxyl on a cellulosesubstrate. FIG. 10B depicts a covalent urea bond from the reaction of anfpPCM isocyanate and amine from another material. FIG. 10C depicts acovalent urethane bond from the reaction of an fpPCM isocyanate on theend of a side chain and hydroxyl from a cellulose substrate. FIG. 10Ddepicts a covalent urea and urethane bonds from the reaction of aminefunction, fpPCMs, multifunctional isocyanate crosslinker/binder, andhydroxyl from a cellulose substrate.

Use of Precisely Branched fpPCMs

In addition to the above disclosure concerning functional polymericphase change material application and the use with various substrates,the disclosure below focuses on how using a more precisely branchedpolymer can give more precise and repeatable control of a copolymeraddition. It is contemplated that each of the embodiments shown in FIGS.7-10 may be modified to utilize the precisely branched polymersdisclosed and discussed below. One of skill in the art would readilyrecognize how to incorporate the precisely branched polymers into theexamples above and into variations of the above examples.

Standard polymerizations do not give precise and repeatable control ofthe comonomer addition because the catalysts generally add co-monomersin a random fashion. As discussed above, many polymers currentlyavailable commercially have random monomer incorporation. Currentcatalysts and polymerization technologies produce polymers with“drifting copolymer” structures where polymer chains in the product havea wide range of compositions of the comonomers. Due to the randomness ofthis comonomer addition, less control can be exerted over the thermalproperties of the copolymer such as melt/crystallization temperature andthe amount of crystallization. The amount of crystallization can beexpressed as a percentage crystallinity, latent heat, heat of fusion orJoules per gram.

Precise branching control as discussed below allows for greater latentheat content at a given melt temperature versus random comonomerincorporation which requires more comonomer to give the same melttemperature, leading to lower percentage crystallinity and lower latentheat.

With general reference to FIGS. 11-13, various graphs are shown thatillustrate the difference in both melt temperature and latent heat. InFIGS. 11-13 the precisely branched polymers are labeled as ADMET. In thevarious embodiments, figures and examples, ADMET stands for AcyclicDiene Metathesis Polymerization and generally represents polymers withprecisely placed methyl branches.

It is well known in the industry, that for polyolefin polymers themelting temperature and latent heat are controlled by the longest carbonsegments in the polyolefin backbone. For instance in polyethylene randomcopolymers, the distribution of ethylene sequences vary. In the case ofpolyethylene copolymers, thick crystal lamella can be formed from thelonger ethylene sequences which will result in higher meltingtemperatures. The shorter ethylene sequences and/or branches will not beincorporated into these crystallites or lamella resulting in loweredheats of fusion or Joules per gram.

In accordance with one embodiment and example, a precisely branchedpolyethylene material having equal ethylene sequences yields thefollowing features: a faster decrease in melting temperature at lowerbranch content; better control of the melting temperature; and anoverall higher amount of ethylene sequences incorporated into thelamella or crystallite, yielding higher latent heats. Use of theseprecisely controlled copolymers yields materials with phase changematerials exhibiting enhanced temperature regulating, heat absorbing,and heat releasing properties. In order to obtain an embodiment of a PCMwith melting temperatures suitable for use in electrochemical deviceapplications and as described below, many embodiments have PCMs with alatent heat of fusion of >10 Joules per gram and other specificallyof >60 Joules per gram. PCMs have a latent heat of fusion of >25 Joulesper gram in one embodiment, >5 Joules per gram in another embodiment,and between 5 and 150 Joules per gram in yet another embodiment, a PCMin one example has a structure with one or more of the followingfeatures:

-   -   The overall polymer molecular weight (n) is between        100-10,000,000, between 1000-1,000,000 or between 10,000-500,000        in various embodiments.    -   With the molecular weight distribution expressed as        polydispersity or Pd=Mn/Mw, it is between 1-100, between 1-10,        or between 1-5 in various embodiments.    -   The ethylene length between branches is between 5-500,000,        between 10-400,000, or between 10-20 in various embodiments.

The length described above can be expressed in a number of ways such asnumber of m units in diagram 1 below, branches per 1000 carbons(branches/1000 C), mole % branches or weight % branches. The PCMstructure also has the following characteristics in one or moreembodiments:

-   -   The number of m units is between 0-500,000, between 0-200,000 or        between 5-15,000 in different embodiments.    -   There are between 200-0, between 100-5 or between 100-0 branches        per 1000 carbons (branches/1000 C) in different embodiments.    -   The mole % of the branches is 0-50% or between −30% in different        embodiments.    -   The weight percentage of the branches is between 0-50% or        between 10-30% in different embodiments.

In some embodiments the branches may be methyl branches from propyleneas the comonomer and propylene may be 0-30 mole % of the polymer. Inanother embodiment, propylene may be 0-39 weight % of the polymer

In diagram 1 above, illustrating one embodiment, R¹ may be any of CH₃,C₂H₅, CnH₂n+1, OCH₃, OC₂H₅, or any functional group, polar group,halogen group, their normal, branched or mixed group. In certainembodiments R² is selected from either CH₃ or OCH₃. In diagram 1, R²═H,CH₃ and in certain specific embodiments, R² is limited to H.

In diagram 1, R³=H, CH₃ or some concentration of a selected functionalgroup, polar group or halogen group. In certain embodiments, R³ islimited to CH₃ or to one or more concentrations of a functional group

In diagram 1, R⁴ and R⁵ are polymer end groups and can be H, CH₃ or anyfunctional group, polar group or halogen group, salt, metal, catalystend, crosslinking group, another polymer chain to form copolymers(block, graft, etc.). In some embodiments, R⁴, R⁵ can be the same ordifferent. In certain embodiments, R⁴ and R⁵ are limited to H, CH₃ orany functional group.

In accordance with other aspects R¹, R², R³, R⁴, and R⁵ can have somedegree of stereocontrol or stereochemistry associated with them. Forexample:

-   -   R¹, R², R³ may be atactic, isotactic or syndiotactic.    -   R¹, R², R³ may also be controlled for chirality to yield L- and        D-chiral homo and copolymers (or another way of stating is R-        and S-polymers).

Different polymer architectures based on the stereochemistry of thepolymer chain can lead to various crystalline complexes. For example,syndiotactic homo- and copolymers can complex with isotactic homo- andcopolymers. Polymers of opposite chirality can be mixed to form aracemic stereocomplex. In one embodiment, a certain amount of isotacticL-polymer can be mixed with an amount of isotactic D-polymer to yield aracemic stereocomplex with thermal and physical properties differentthan the L- or D-chiral homopolymers. (A polymer stereocomplex isdefined as a stereoselective interaction between two complementingstereoregular polymers, that interlock and form a new composite,demonstrating altered physical and thermal properties different than theparent polymers.)

These syndiotactic, isotactic or L- and D-chiral segments can be indifferent polymer chains (homopolymer segments) or in the same polymer(stereoblock copolymers segments). The syndiotactic, isotactic or L- andD-chiral segments can make up anywhere between 1-100% of the polymer orcopolymer as well as various intermediate percentage ranges.

The syndiotactic, isotactic or L- and D-chiral segments can be mixed ina ratio between 9:1 and 1:9 to give complete or partial stereocomplexformation and subsequent thermal and physical property adjustment. Othercrystalline complexes may also be utilized such as complexes betweendifferent polymers such as polyamides and polyesters, cationic/anionic,polyethers/polyacids, and triple helixes.

R³, R⁴, R⁵ can be any functional group, polar group or halogen group,salt, metal, catalyst end, crosslinking group, or any of the followingfunctional groups: acid anhydride groups, amino groups, N-substitutedamino groups and their salts, amide groups, imine groups, imide groups,azide groups, azo groups, amine-formaldehyde groups, carbonyl groups,carboxy groups and their salts, cyclohexyl epoxy groups, epoxy groups,glycidyl groups, hydroxy groups, isocyanate groups, cyanate groups ureagroups, aldehyde groups, ketone groups, ester groups, ether groups,alkenyl groups, alkynyl groups, thiol groups, disulfide groups, silyl orsilane groups, halogenated leaving groups, peroxide groups, salt groups,groups based on glyoxals, groups based on aziridines, groups based onactive methylene compounds or other b-dicarbonyl compounds (e.g.,2,4-pentandione, malonic acid, acetylacetone, ethylacetone acetate,malonamide, acetoacetamide and its methyl analogues, ethyl acetoacetate,and isopropyl acetoacetate), halo groups, hydrides, or other polar or Hbonding groups and combinations thereof.

The crosslinking groups discussed above may also include the ability toreversibly or irreversibly change the crosslink by thermal, sonic,photon, pressure, or chemical (water, solvents, ions, etc.) energy.

Various other methods of functionalization are described shown in thefollowing references, the details of which are incorporated by referenceinto the present application: Synthesis of Functional Polyolefins usingMetallocenes: A Comprehensive Review; Atiqullah M., et. al.; PolymerReviews, 50:178-230, 2010; Comprehensive Organometallic Chemistry III:11.20-Polymerization of Alkenes; Elsevier Ltd.; Fujita T., Makio H.;Vol. 11, 691-734, 2007; Functionalized Ethylene Copolymers and Materialsvia Olefin Metathesis Polymerization; Baughman, T., Univ. of FloridaDissertation, 2006.

In accordance with another aspect, the polymer may have a certain degreeof unsaturation or include double and triple bonded atoms in thepolymer. For instance, alkene or alkyne bonds. This unsaturation (notall valence electrons are “saturated” or reacted to other atoms) can beincorporated and controlled by the monomers used in the polymerization(isoprene, butadiene, α-olefins, etc.), hydride elimination (β-hydrideelimination, etc.), various polymerization mechanisms (ring-openingmetathesis polymerization (ROMP), acyclic diene metathesis (ADMETdescribed herein, etc.) or controlled hydrogenation/dehydrogenation. Forinstance, as shown in Diagram 2 and FIG. 14, examples of making thedisclosure by ADMET polymerization and subsequent hydrogenation areshown. FIG. 14 shows the effect of unsaturation on the thermalproperties.

As can be seen, unsaturation causes a lower melting temperature and alsoslightly lower latent heat of fusion, but by controlling the level ofunsaturation, one can also control the thermal properties. In someembodiments the unsaturation is 0-99 mole %. In other embodiments theunsaturation is 0-15 mole %. In various other embodiments, variousintermediate ranges of mole % are utilized.

The isomeric orientation of the double bond can also have an effect onthe properties of the unsaturated polymer. The cis/trans orientation ofthe double bond can also be controlled by the hydrogenation catalyst orthe hydrogenation process conditions such as time, temperature,pressure, etc.

The isomer ratio, unsaturation and double bond orientation will varydepending on the comonomer composition, comonomer distribution andpolymerization conditions. One goal of a composition in accordance withan aspect of the present disclosure is to maximize latent heat in thepreferred temperature range.

Copolymer segments used in connection with aspects of the presentdisclosure can be copolymers or blended with any of the otherpolymers/copolymers disclosed herein. In addition, copolymer segmentsused in connection with aspects of the present disclosure can be highmelt or low melt.

Use of Nucleating Agents

In order to improve the crystallinity of the PCM, pPCM and/or fpPCM andtherefore the latent heat and thermal conductivity of these materials,nucleating agents can also be added. Nucleating agents can effectimproved crystal growth, crystallization speed, crystal shape and size,amount of crystallization and number of crystallites of the materials.

Furthermore, the particle size of the nucleating agent and the mixing ofthese are important factors in ensuring optimal performance of theadditives. Features of a good melt insensitive nucleating agent may beselected from one or more of the following:

-   -   It contains both an organic group and a polar group    -   It is well dispersed    -   It is insoluble or can become insoluble in the polymer    -   It has an epitaxial match with the PCM crystal    -   The physical or chemical nature of nucleating agents can be        diverse. A nucleating agent can be:        -   An impurity, i.e. catalyst residue        -   An organic compound like benzoic acid, hydrocarbons or fatty            acid based materials        -   An inorganic compound such as mineral or pigment        -   A foreign polymer crystal, i.e. polyethylene for octadecane,            etc.        -   A diluent, i.e. a material that lowers the Tg or improves            the chain mobility leading to improved chain packing.

Additional nucleating agents that may be utilized include thosedescribed in U.S. Pat. No. 7,569,630 β-Crystalline Polypropylene toChemtura Corp., U.S. Pat. No. 7,879,933 Blending Nucleating AgentsComposition and Methods to Milliken & Company, and Hyperform® productsfrom Milliken & Company. Other examples are aliphatic hydrocarbons,aromatic hydrocarbons, alcohols, fatty acids, fatty acid salts, fattyacid esters, fatty amides, fatty amines, fatty alcohols,N-Phenyl-N′-stearylurea, zinc glycerolate, benzoic acid, salts andesters of benzoic acid, benzoic acid derivatives, Na benzoate, Libenzoate, Al hydroxy-4-tert.-butyl benzoate, phosphate esters, phosphateester salts, sodium2,2′-methylene-bis-(4,6-di-tert-butylphyenyl)phosphate, dibenzylidenesorbitol, derivatives of dibenzylidene sorbitol, linear or branchedpolyphenyls, salts of hydrogen phthalate, 1, 2-cyclohexanedicarboxylicacid and the mono or di neutralized salt (i.e. Na, K, Al, B, Ti, Zn, Ca,Li, Mg, etc.), cetyl alcohol, stearyl alcohol, eicosanol, myristic acid,palmitic acid, behenic acid, stearic acid amide, ethylenebisoleic acidamide, methylolbehenic acid amide, 1-octacosanol, 1-heptacosanol,1-hexacosanol, 1-pentacosanol, 1-tetracosanol, 1-tricosanol, 1-docosanol, 1-heneicosanol, 1-eicosanol, 1-nonadecanol, 1-octadecanol,1-heptadecanol, 1-hexadecanol, 1-pentadecanol, 1-tetradecanol,1-tridecanol, tridecylamine, tetradecylamine, pentadecylamine,hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine,eicocylamine, heneicocylamine, dococylamine, tricocylamine,tetracocylamine, pentacocylamine, hexacocylamine, heptacocylamine andoctacocylamine, etc. Minerals such as talc, kaolin, calcium carbonate,TiO₂, salts, NaCl, and Na carbonate may also be used as nucleatingagents. These compounds may be used singly or in combination of two ormore thereof.

Microcapsules and Other Containment and/or Absorbing Structures forPhase Change Materials

PCM can be contained in microcapsules or some other containmentstructure or particulate. Containment structures other thanmicrocapsules are capable of carrying functional groups, either as anatural part of their structure or from their modified manufacturing.For instance, PCMs can be absorbed and stabilized into any number ofparticles including silica (fumed or precipitated), graphite, graphene,carbon nanoparticles, carbon or activated carbon, zeolites, organoclays,montmorillonite, bentonite, clay, talc, and vermiculite. Paraffin orhydrophobic PCMs can also be absorbed in any number of polymers,especially crosslinked polymers, similar to how a plasticizer willabsorb into plastics. For instance PCM can be absorbed into anypolyolefin and polyolefin copolymer such as polyethylene, polypropylene,salts of polyolefins and their copolymers, poly(meth)acrylates, salts ofpoly(meth)acrylates, polyvinyls, aliphatic polyesters, rubbers,copolymers (i.e. Kraton® copolymers, Elvaloy®) and mixtures, etc. PCMsbased on glycols can be absorbed into any hydrophilic polymers such aspolyvinyl alcohol, substituted cellulose (CMC, HMC, etc.) etc.

PCMs, pPCMs, fpPCMs can also be contained, absorbed or infused on anyparticle or fiber including the below described thermal conductivefillers, reinforcing materials, fire retardant additives, etc. Thesecontainment or absorbing particle can be any shape such as round,spherical, cylindrical, fiber, sheet, flake, powder, whiskers, tubular,platelets, foams, meshes, agglomerates of these shapes or any otherirregular shape. Depending on the application, a single shape or mixtureof shapes may be advantageous to provide the optimum packing andarrangement for particle contact. These containment or absorbingparticles can be any size, but in certain embodiments of the presentdisclosure, may be 0.1 nm to 100 mm.

Other materials which can absorb or contain PCMs such as standardsuperabsorbent polymers based on cross-linked sodium polyacrylate. Othermaterials are also used to make a superabsorbent polymer, such aspolyacrylamide copolymer, ethylene maleic anhydride copolymer,cross-linked carboxy-methyl-cellulose, polyvinyl alcohol copolymers,cross-linked polyethylene oxide, and starch grafted copolymer ofpolyacrylonitrile to name a few.

Microcapsules are implemented to contain a phase change material, whichserves to absorb or release heat to reduce or eliminate heat transfer.In particular, the microcapsules are formed as shells that defineinternal compartments within which the phase change material ispositioned. The shells can be formed of any suitable material thatserves to contain the phase change material, thus offering a degree ofprotection to the phase change material against ambient or processingconditions or against loss or leakage during use. For example, theshells can be formed of a polymer or any other suitable encapsulationmaterial.

The selection of a material forming the microcapsule shells can bedependent upon various considerations, such as its affinity for othermaterials in the TMM, affinity or adhesion to batteries, its reactivityor lack of reactivity with the phase change material, TMM materials orbatteries its resistance to degradation under ambient or processingconditions, and its mechanical strength. In particular, for certainimplementations, a material forming the shells can be selected so as toinclude a set of functional groups, acid anhydride groups, amino groups,N-substituted amino groups and their salts, amide groups, imine groups,imide groups, azide groups, azo groups, amine-formaldehyde groups,carbonyl groups, carboxy groups and their salts, cyclohexyl epoxygroups, epoxy groups, glycidyl groups, hydroxy groups, isocyanategroups, cyanate groups urea groups, aldehyde groups, ketone groups,ester groups, ether groups, alkenyl groups, alkynyl groups, thiolgroups, disulfide groups, silyl or silane groups, halogenated leavinggroups, peroxide groups, salt groups, groups based on glyoxals, groupsbased on aziridines, groups based on active methylene compounds or otherb-dicarbonyl compounds (e.g., 2,4-pentandione, malonic acid,acetylacetone, ethylacetone acetate, malonamide, acetoacetamide and itsmethyl analogues, ethyl acetoacetate, and isopropyl acetoacetate), halogroups, hydrides, or other polar or H bonding groups and combinationsthereof. At least some of these functional groups can be exposed onouter surfaces of the shells and can allow chemical bonding to acomplementary set of functional groups included in either of, or both,the substrates or other TMM materials, thereby enhancing durability oradhesion. In such fashion, at least some of the microcapsules can bechemically bonded to other PCMs, pPCMs, fpPCMs or fillers. Thus, forexample, a material forming the shells can include a set of carboxygroups, which can chemically bond to a set of hydroxy groups. As anotherexample, those carboxy groups included in the shells can chemically bondto a set of amino groups.

Examples of polymers that can be used to form the shells include thoselisted under the “polymers” definition, including those with carboxygroups, such as polymers including monomeric units based on acrylic acidor methacrylic acid. For certain implementations, the shells can beformed of a polymer that includes from about 1 to about 100 molarpercent of monomeric units that include carboxy groups, such as fromabout 20 to about 80 molar percent, from about 25 to about 60 molarpercent, or from about 40 to about 50 molar percent of the monomericunits. In some instances, it can be desirable to adjust a molarpercentage of the monomeric units based on sizes of the microcapsules.For example, as a size of an individual one of the microcapsulesdecreases, an outer surface area of that microcapsule also typicallydecreases. Thus, to maintain a desired amount of exposed functionalgroups for chemical bonding, it can be desirable to increase the molarpercentage of the monomeric units as the size of that microcapsuledecreases. As another example, as a size of an individual one of themicrocapsules increases, a weight of that microcapsule also typicallyincreases. Thus, to account for the increasing weight, it can bedesirable to increase the molar percentage of the monomeric units as thesize of that microcapsule increases. Table 1 provides examples of rangesof the molar percentages as a function of the sizes of themicrocapsules. Referring to Table 1, the microcapsules are assumed to bespherical for ease of presentation. Similar considerations and molarpercentages can also apply to polymers with other types of functionalgroups.

TABLE 1 Surface Molar percent of Radius - r area - 4πr² monomeric unitswith (μm) (μm²) carboxy groups 0.5 3 50-60 1 13 45-55 2 50 40-50 3 11340-50 4 201 35-45 5 314 35-45 6 452 30-40 7 616 30-40 8 804 25-35

Other examples of polymers that can be used to form the shells includethose formed of monomers using any suitable polymerization technique.Table 2 below sets forth examples of such monomers that includedifferent types of functional groups.

TABLE 2 Functional Group Monomers Carboxy acrylic acid, methacrylicacid, maleic acid, itaconic acid, citraconic acid, vinylacetic acid,Group p-vinylbenzoic acid, 2-acryloyloxyethylacidphosphate,β-acryloyloxyethyl hydrogen succinnate (or any other anhydride reactedor modified hydroxy group-containing monomer), and any other unsaturatedpolymerizable carboxylic acid Isocyanate isocyanato methacrylate,monomer supplied as TMI by Cytec Industries, 2- Groupmethacryloyloxyethyl isocyanate, acryloyloxyethyl isocyanate, blockedisocyanates such as 2-(0-[1′-methylproplyideneamino]carboxyamino)ethylmethacrylate, and any other unsaturated polymerizable isocyanateAnhydride maleic anhydride, itaconic anhydride, citraconic anhydride,and any other unsaturated Group polymerizable anhydride HydroxyCH₂═CR′COO(CH₂)_(n)OH, where R′ = CH₃ or H, n = 2-4 (e.g., hydroxyethylmethacrylate, Group hydroxyethyl acrylate, hydroxypropyl methacrylate,hydroxypropyl acrylate, hydroxybutyl methacrylate, and hydroxybutylacrylate); CH₂═CR′COO((CH₂)_(n)O)_(z)OH, where R′ = CH₃ or H, n = 1-10,z = 1-1,000 (e.g., glycol based acrylates or methacrylates, such asethyleneglycol methacrylate, ethyleneglycol acrylate, polyethyleneglycolmethacrylate, and polyethyleneglycol acrylate); allyl alcohol;α-ethylallyl alcohol; allylcarbinol;CH₂═CH—(CH₂)_(m)—O—((CH₂)_(n)O)_(z)OH, where m = 0-4, n = 1-10, z =1-1000 (e.g., glycol based vinyl ethers, such as ethyleneglycolmonovinyl ether and polyethyleneglycol monovinyl ether);CH₂═CH—O—CO—((CH₂)_(n)O)_(z)OH, where n = 1-10, z = 1-1000 (e,g., glycolbased vinyl esters, such as ethyleneglycol monovinyl ester andpolyethyleneglycol monovinyl ester); and any other unsaturatedpolymerizable hydroxy group-containing monomer Epoxy glycidylmethacrylate, glycidyl acrylate, allyl glycidyl ether, 2-vinyloxyethylglycidyl Group ether, and any other unsaturated polymerizableepoxy-group containing monomer Amino or acrylamide; methacrylamide; N-CH₂═CR′CONHCH₂OX, where R′ = CH₃ or H, X = H, methoxy, ethoxy, propoxy,Substituted isopropoxy, butoxy, or isobutoxy; and Amino vinylamine; andany other unsaturated polymerizable amino group-containing monomer GroupSilyl methacryloxpropyltrimethoxysilane,methacryloxypropyltriethoxysilane, Groupmethacryloxypropyltributoxysilane, triethoxyvinylsilane,trimethoxyvinylsilane, triacetoxyvinylsilane, triisopropoxyvinylsilane,tris(methoxyethoxy)vinylsilane, and any other unsaturated polymerizablesilane

Microcapsules can also be multi-walled or have multiple shell layers.The inner layer should provide the required strength, durability andcontainment while the outer layers provide compatibility or adhesiveproperties. The outer wall of the microcapsule can be a thermoplasticpolymer which can melt or soften at desired temperatures to flow, actlike a viscous liquid or fuse the microcapsules to substrates, othermicrocapsules or other TMM materials. The thermoplastic outer wallshould have a melting or glass transition temperature (Tg) below thetemperature which will damage the wall of an electrochemical cell, butabove normal use temperatures. The outer wall can be made of any polymerthat melts, softens or flows such as polyolefins, rubbers, polyvinyls,poly(meth)acrylates, polyurethanes, etc. or copolymers.

Microcapsules can have the same shape or different shapes, and can havethe same size or different sizes. In some instances, the microcapsulescan be substantially spheroidal or spherical, and can have sizes rangingfrom about 0.1 nm to about 1,000 microns, such as from about 0.1 nm toabout 500 microns, from about 0.1 nm to about 100 microns, from about 1to about 15 microns. For certain implementations, it can be desirablethat a substantial fraction, such as at least 50 percent, or at least 80percent of the microcapsules have sizes within a specified range, suchas from about 1 to about 15 microns. It can also be desirable that themicrocapsules are monodisperse with respect to either of, both, theirshapes and sizes.

Microcapsules can be of a durable, breakable, or controlled releasetype. It can be advantageous to have the microcapsule core materialpermanently contained to prevent leakage or loss of core material duringuse or processing. It may also be advantageous to have the core materialreleased thru either fast (breakable) or slow (controlled release)means. For instance, when microcapsules are added to composites, and thecomposites are cured at higher temperatures, small voids can be formedbetween the composite and microcapsule shell wall due to variables suchas differential expansion between microcapsule and composite,incompatibility between microcapsule and composite or shape distortion,etc. Release of core material and allowing it to flow into and fillthese voids allows for greatly improved thermal conductivity. This isshown in FIGS. 15A-15B.

Selection of a PCM Transition Temp.

The selection of a PCM is typically dependent upon the transitiontemperature that is desired for a particular application that is goingto include the PCM. The transition temperature is the temperature orrange of temperatures at which the PCM experiences a phase change fromsolid to liquid or liquid to solid. For example, a PCM having atransition temperature near the normal range of temperatures thatbatteries reach during multiple charge and discharge cycles can bedesirable for battery applications to prevent overheating, thermalrunaway, and fires. A phase change material according to someembodiments of the disclosure can have a transition temperature in therange of about 5° C. to about 120° C. In one embodiment, the transitiontemperature is about 10° C. to about 80° C. In another embodiment, thetransition temperature is about 30° C. to about 70° C. In anotherembodiment, the PCM has a transition temperature of about 40° C. toabout 60° C. In another embodiment, the PCM has a transition temperaturebetween 25° C. and 140° C. In certain embodiments, such as embodimentswhere multiple layers of PCMs are used in one casing, for the dualpurposes of protecting a cell from extreme cold and for absorbing excessheat during operation, one or more of the PCMs may have a transitiontemperature in the range of −60° C. to 60° C.

The transition temperature can be expanded or narrowed by modifying thepurity of the PCM, molecular structure, blending of PCMs, blending ofmPCM, blending of polymeric PCMs and any mixtures thereof.

In addition, the temperature control is dependent on the absorption andrelease of energy by changing phases, preferably by absorbing energy andmelting or releasing/dissipating heat by solidifying or crystallization.These melting (Tm) and crystallization (Tp) temperatures for a singlePCM material in embodiments of this disclosure is not widely spread(“supercooling”). This difference can be defined as the differencebetween peak melting temperature and peak crystallization temperature asmeasured by a DSC., i.e. ΔT (° C.)=Tm-Tc. In some embodiments this ΔT is<30° C., in others <15° C., in others <10° C., and in yet others <5° C.

Mixing and Layering of PCM Transition Temperatures

In some embodiments, it may be advantageous to have multiple or broadtransition temperatures. If a single narrow transition temperature isused, this can cause thermal/energy buildup before the transitiontemperature is reached. Once the transition temperature is reached, thenenergy will be absorbed until the latent energy is consumed and thetemperature will then continue to increase. Broad or multiple transitiontemperatures allow for temperature regulation and thermal absorption assoon the temperature starts to increase, thereby alleviating anythermal/energy buildup. Multiple or broad transition temperatures canalso more efficiently help “bleed-off” or conduct heat away from abattery by overlapping or staggering thermal absorptions. For instance aTMM contains PCM1 which absorbs at 35-40° C. and PCM2 which absorbs at38-45° C. PCM1 will start absorbing and controlling temperature until amajority of the latent heat is used, at which time PCM2 will start toabsorb and conduct energy from PCM1 thereby rejuvenating PCM1 andallowing it to keep functioning. Alternatively, layering of multiplePCMs may be utilized to achieve both the dissipation of heat from anoperating cell and protection of the cell from extremely cold ambienttemperatures. The transition temperatures required for each function maydiffer greatly. This broadening or mixing of transition temps can bedone by combining all materials or layering them as depicted in thevarious figures.

Selection of Latent Heat Values

The selection of the phase change material can be dependent upon alatent heat of the phase change material. A latent heat of the phasechange material typically correlates with its ability to absorb andrelease energy/heat or modify the heat transfer properties of thearticle. In some instances, the phase change material can have a latentheat that is at least about 10 J/g, such as at least 20 J/g, as at leastabout 40 J/g, at least about 50 J/g, at least about 70 J/g, at leastabout 80 J/g, at least about 90 J/g, or at least about 100 J/g. Thus,for example, the phase change material can have a latent heat rangingfrom about 10 J/g to about 60 J/g, from about 20 J/g to about 400 J/g,such as from about 60 J/g to about 400 J/g, from about 80 J/g to about400 J/g, or from about 100 J/g to about 400 J/g.

TMM Rheology, Viscosity, Elasticity, Crosslinking and PhysicalProperties of the PCM

The rheology (i.e. viscosity or flow properties) of the TMM is importantfor many different processes of the application to electrochemical cellsand packs. Variables such as general application of the TMM to the cellsor packs either by inserting the cell into a sleeve or casing, wrappinga cell with tape or film, or otherwise applying with spray, flow,coating, pressure adhesive or extrusion is controlled by the rheology.The application must balance rheology to achieve sufficient gap fill andreduction of air spaces for good thermal conductivity versus maintainingthe structure and stability of the TMM on a cell or pack. That is, thematerial should not allow a tube, sleeve, casing, film, tape, or othersurrounding material to slide off the cell.

TMM with phase change and/or polymeric properties are advantageous insolving the above problems since they can be formulated to be solid atlow temperatures and deformable or flowable at phase change or highertemperatures. The phase change temperature can be lower, equal to orhigher than the normal operating temperature of the battery cell orbattery pack. These TMM embodiments of tubes, sleeves, and wrapped filmand tape are also advantageous over greases or waxes alone in thatimproved physical properties such as tensile strength, elongation,flexibility, toughness can be improved.

Rheology, viscosity, elasticity, and flow of the TMM can be controlledby many different variables. These can include the characteristics ofthe pPCM/fpPCM such as type of polymer, the polymer structure, thepolymer mol. wt., polymer branching (i.e. number of branches, length ofbranches, types of branches, etc.), polymer functionality (i.e. type andamount), copolymers, compatibility with other polymers, crosslinking ofthe polymer, type of crosslinking, entanglement of the polymer,compatibility with additives, etc.

One way in which the elasticity of the TMM can be controlled is throughthe section of polymer materials with elastomeric properties. Suchelastomeric materials include polyolefin copolymers such as copolymersof polyethylene with any C₃-C₃₀ α-olefin, or vinyl acetate, other vinylmonomers such as styrene or its analogues, acrylate or methacrylatemonomers, vinyl ether monomers, vinyl ester monomers, acrylonitriles,rubbers and copolymers made from isoprene, butyl, etc., or combinations,blends, mixtures thereof. Additionally, the TMM may be made of polymerelastomers such as polyesters, silicon rubbers or polyurethanes.Non-inclusive examples of these are Hytrel® polyesters from DuPont®,Spandex®-type polyurethanes and RTV or LTV type silicon rubbers.

An additional way that the elastomeric properties may be influenced isby crosslinking. In certain embodiments, the TMM and the PCM may becrosslinked with an average of 0.05-1 crosslinks per polymeric chain.

The polymer glass transition temperature (Tg, temperature at which apolymer changes from a glassy state to a rubbery state) can becontrolled to allow for flow at or below operating temperatures. The Tgcan be between −20° C. and 150° C., preferably between 15° C. and 90° C.

The polymer mol. wt. can be controlled to provide low or high viscositywith higher mol. wt. polymers providing low viscosity or no flow. Themolecular weight of pPCM/fpPCM in some embodiments can be at least 500Daltons, and in other embodiments can be at least 2000 Daltons. It ispossible that in some embodiments, Mol. wts. can range from 500 Daltonsto millions of Daltons, as exemplified by the use of ultrahigh mol. wt.polyethylene (UHMWPE)

The polymer branching can be controlled to provide for chainentanglement and rheology control. The polymer chain can have any numberand length of chains. The polymer may have 0-1000 branches. The branchesare at least 50 Daltons. The branches can be in any configuration suchas random, comb, etc. The branches can be in a stereospecificconfiguration.

The polymer can be a copolymer or block copolymer in which there are“hard” segments and “soft” segments. The hard segments can be due tohigh Tg moieties or crystallizable moieties, whereas the soft segmentscan be due to low Tg moieties or amorphous segments. The hard segmentscan interact and create a crosslink, entanglement or interaction thatcreates a degree of fixation or high viscosity. The soft segment can befree to flow or rearrange due to heat or pressure.

In one embodiment, the weight of the crystallizable section forms atleast 20%, in other embodiments at least 50%, and in yet otherembodiments at least 70% of the total weight of the pPCM/fpPCM.

They type and amount of functionality can also effect the rheology, flowproperties and setting of the TMM. For instance, the TMM can be appliedto the electrochemical cell or pack, then fully cured and crosslinkedthrough any of the previously described functionality, reactions orcrosslinking mechanisms.

The functionality can be also be mixed to give different crosslinkingreactions and different kinetics of the crosslinking reactions. Asexample, epoxy and amines can quickly cure at room temperature toprovide for a fast set, tack free time, and use. This partial cureallows for slight flow or gap fill either over time or as the TMM warmsup from battery cell charge and discharge cycles—at this time, a secondset of crosslinking reactions can occur to fully crosslink and fully setthe TMM. These second set of crosslinking reactions can be triggeredeither by oxidation, heat, UV etc. such as oxygen radical crosslinkingof unsaturated groups, N-methylol ether crosslinking with hydroxyl orcarboxyl, or UV initiated free radical reaction with unsaturatedmoieties.

The different crosslinking reactions and kinetics can be controlled bythe use of different catalysts or initiators that react at differenttemperatures. For instance, two different free radical (FR) initiators(peroxide, azo, etc.) with different decomposition temperatures can becombined with a polymer containing various unsaturated groups. The firstFR initiator can decompose at application temperatures creating apartial cure, crosslinking or set while allowing for some flow and gapfill. The second FR initiator can then decompose and react to furtherreact at higher temperatures.

These various temperatures of reaction, application or use can also becontrolled by external environments. For instance, room temperaturecrosslinking reactions can be controlled by preparing, shipping/storingand applying the TMM at lower than room temperature or at freezingtemperatures, then allowing the reaction to proceed as batteries areinstalled in their devices or as battery packs are assembled. Likewise,crosslinking reactions can be controlled by the addition of heat, lightor other forms of energy.

Rheology, viscosity, flow and gap fill can also be controlled by the useof reversible reactions or crosslinks. These are sometimes referred toas “self-healing” systems. For instance, the TMM can contain ioniccrosslinks based Zn⁺² carboxyl salts or S-S disulfide bonds that caneasily break, allow flow and recombine.

Examples of reversible reactions are hydrolysis of ester bonds, breakingand recombination of the urethane bond into hydroxyl and isocyanate,breaking and recombination of the urea bond into amine and isocyanate,Diels-Alder reaction based crosslinks, ionic bonds based on metals,metal coordination or organic salts, hydrogen bonding, metalcoordination, hydrophobic forces, van der Waals forces, pi-piinteractions and electrostatic effects.

The above described phase changes or chemical associations can also beused as reversible crosslinks, i.e. the melting and recrystallization ofpolymer crystalline segments. Associations of hydrophobic/hydrophilicsections of copolymers or block copolymers. Copolymers or blockcopolymers with different Tg segments, hard/soft segments, etc.

Rheology, viscosity, flow and gap fill can also be controlled by the useor addition of rheology control agents, thickeners, etc. These materialsare such things as silica, carbon particles, talc, ZnO, Calciumcarbonate, partially crosslinked or gelled polymers, etc. The followingdescribed particles and fillers can also be used a rheology control orviscosity agents.

Fillers and Additives—Thermal Conductive Fillers

Aspects of the present disclosure pertain to using a thermal conductivefiller in combination with the various phase change materials describedherein. As described above, Thermal Conductivity, k (also denoted as λor κ), is the property of a material's ability to conduct heat ismeasured in W/m·K.

Thermal conductivity is defined as the quantity of heat (Q) transmittedthrough a unit thickness (L) in a direction normal to a surface of unitarea (A) due to a unit temperature gradient (AT) under steady stateconditions and when the heat transfer is dependent only on thetemperature gradient.

The TMM described herein can also have various conductive additives andfillers to improve the various properties. Materials to enhance thethermal conductivity can be added such as forms of carbon (graphene,graphite (synthetic or natural, expanded or exfoliated, etc.), graphiteoxide, diamond (synthetic or natural), diamond aerogel, carbon fibers,carbon nanotubes (CNT or single walled (SWCNT)), multiwalled (MWCNT)),fullerenes (buckyballs), loonsdaleite, carbine, glassy carbon, amorphouscarbon and their various forms of oxides or other functionalized forms.Other thermal conductive particles can include highly crystalline orhighly oriented organic materials and polymers such as high densitypolyethylene (low mol. wt. or UHMWPE, such as Dyneema® fibers orSpectra® fibers), polybenzobisoxazole (PBO or Zylon®), poly(p-phenylenebenzobisthiazole) (PBT), and any other liquid crystalline polymer(LCPs), metals, metal salts, metal carbides, metal oxides, metalnitrides, metal sulfate derivatives, metal phosphate derivatives, boronnitride (cubic and hexagonal), boron carbide, boron oxide, alumina, Al,Al oxide, Al₂O₃, Al nitride, Ag, Au, metallized glass, Sn, Zn, ZnO, Cu,Mg, MgO, wollastonite, silica (fused, fumed, precipitated, coated,colloidal, agglomerated),silicon carbide (SiC), silicone, silica coatedparticles and alloys (silica coated Al nitride), sapphire, quartz,polyhedral oligomeric silsesquioxane (POSS), Fe, Fe oxides, Pt, Pb, Ni,Ti, Ti oxides, Cr, Bi, In, Ga, Ge, Ce, La, W, WC, Li, Be, Be oxides, Ca,Rb, Sr, Cs, Ba, Fr, Ra, Sc, V, Mn, Co, As, Se, Y, Zr, Zr oxides Nb, Mo,Tc, Ru, Rh, Cd, In, Sb, Te, Hf, Ta, Re, Os, Ir, Hg, Tl, Po, Rf, Db, Sg,Bh, Hs, Mt, Ds, Rg, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, etc. andtheir blends, solders, eutectics and alloys.

Low melting or fusible materials and fillers can also be included forenhancement of rheology, gap fill, and conductivity (electrical andthermal). These may comprise Ga, In, Sn, or any alloy and oxide thereof.The low melting metal may optionally further comprise Ag, Bi, Cd, Cu,Pb, Zn, or a combination thereof. Examples of suitable low meltingmetals, alloys and their oxides include Ga, In—Ga alloys, In—Ag alloys,In—Bi alloys, In—Sn alloys, Bi—Sn alloys, Pb—Sn alloys, In—Pb alloys,In—Pb—Ag alloys, In—Bi—Sn alloys, Sn—In—Zn alloys, Sn—Bi—Zn alloys,Sn—In—Ag alloys, Sn—Ag—Bi alloys, Sn—Bi—Cu—Ag alloys, Sn—Ag—Cu—Sballoys, Sn—Ag—Cu alloys, Sn—Ag alloys, Sn—Ag—Cu—Zn alloys, andcombinations thereof. The low melting metal can have a melting point ofup to 250° C., alternatively up to 225° C. The low melting metal canhave a melting point of at least 50° C., alternatively at least 150° C.The low melting metal can be a eutectic alloy, a non-eutectic alloy, anoxide, or a pure metal. Low melting metals are commercially available.The low melting metal may comprise at least about 0.1 up to about 20% ofthe weight of the TMM. These alloys, oxides or metals can also beseparate layers or segregated portions of the TMM.

The thermal conductive fillers work most efficiently if they are inclose contact or touching other thermally conductive or crystallinematerials in order to facilitate a direct conductive pathway. Thereforethe concentration, impurities, crystallinity, shape, size, compatibilityand distribution of the fillers and other thermal materials isimportant.

The fillers can be 2-95% of the TMM. The amount of filler will depend onmany factors such as compatibility, effect on rheology, etc. Theparticle can be any shape such as round, spherical, cylindrical, fiber,sheet, flake, powder, whiskers, tubular, platelets, foams, meshes,agglomerates of these shapes or any other irregular shape. Depending onthe application, a single shape or mixture of shapes may be advantageousto provide the optimum packing and arrangement for particle contact.

The particle can have any aspect ratio, from 1 for perfectly sphericalparticles to an infinite aspect ratio for nanomaterials. The particlesize can be from 0.1 nanometer to 1 mm. The size and distribution of theparticle will depend on the application such as nanometer sizedparticles allow for good dispersion, compatibility with good gap fillwhereas large particles allow for lower concentration but provide forhigher occurrence of contact between the particles for good thermalconductivity. Depending on the application, a single particle size ornarrow particle size distribution may be advantageous for rheologyoptimization, whereas a mixture of particle sizes allows for mostefficient packing distribution curve. For instance smaller averageparticles can fill the interstitial spaces between larger averageparticles to produce the optimum packing theory distribution curve whichprovides for efficient thermal transfer.

The particles can be of a monomolecular thickness, layer or size, suchas the individual platelets or layers which make up bigger particles. Asan example, graphene is one-atom-thick planar sheets of sp²-bondedcarbon atoms that are densely packed in a honeycomb crystal lattice.Graphene sheets stack to form graphite.

Thermal conductivity can be improved by using materials that will alignor orient themselves to connect and provide a pathway from theelectrochemical cell or pack to a cooler surface. For instance the useof fibers, whiskers, flakes, foams, or sheets can be used such that thematerials when applied will align radially with respect to eachcylindrical cell. Further examples are using fibers, flakes, foams, orsheets that have a length equal or greater than the TMM thickness sothat the one end of the fiber, flake, foam, or sheet is touching thecell and the other end reaches to the surface or contacts the coolersurface, heat sink or heat spreader providing a constant unbroken singleparticle pathway. Alternatively, fibers, flakes, foams, or sheets couldalign longitudinally with multiple cells within a pack to move heat awayfrom areas in between multiple cells. These types of fillers can alsoprovide strength and reinforcement to the TMM to improve the tensile,adhesive or cohesive properties.

In order to provide optimum thermal conductivity, the fillers shouldhave maximum purity with reduced included elemental materials. Puritiesgreater than 95%, preferably >99% and most preferably >99.99999%. Higherpurities also lead to higher material crystallinity with >50%crystallinity, preferably >90% and most preferably >99% crystalline.Reduced elemental impurities also means lower radioactive emissions withradioactive particle emissions lower than 0.001 counts/cm²·hr, (i.e.positively charged alpha particle (a), a positively or negativelycharged beta particle (β), a photon or gamma particle, (γ), or a neutronand neutrinos).

In order to improve filler or particle compatibility with the TMM,electrochemical cells, or matrix material, it can be advantageous tosurface treat the particle. This can also improve the rheology,viscosity and flow characteristics of the TMM. Surface treated particlescan have improved compatibility with the binder, polymers or matrixmaterial of the TMM which allows for complete coverage or surfacewetting of the particle and therefore less air space or voids around theparticle providing for improved thermal conductivity. Particle surfacetreatments can be by reaction with coupling agents, oxidation, acid,base, flame, functionalizing, etc. plasma oxidation, plasma sulfonation,ozone treatments in the presence or absence of ultraviolet light,alkaline surface hydrolysis, silanation, silanization and plasma ammoniatreatment.

Coupling or surface treating agents can be any functional material suchas fpPCMs, fpPCM with salt functionality, nonionic molecules withhydrophilic or hydrophobic moieties (i.e. aliphatic ethoxylates, alkylethoxylates, alkylphenoxy ethoxylates and their branched analogues),anionic or cationic molecules or polymers such as those containingcarboxyl groups, containing amine neutralized carboxy groups, containingamine groups, acid neutralized amine groups etc. anhydrides andunsaturated polymeric acids or their salts and analogues (i.e.maleinized polybutadiene, maleinized or acid functional polyolefins,maleinized or acid functional poly (meth)acrylates, maleinized or acidfunctional polyesters, including metal or amine salts), alkoxysilanes,alkoxy-functional oligosiloxanes, alkylthiols, fatty acids, fatty acidmetal salts, fatty acid amine salts, fatty amines, fatty amine salts,titanates, titanate coupling agents, zirconates, zirconate couplingagents, aluminates, aluminate coupling agents or mixtures thereof.Coupling agents such as those supplied by Kenrich Petrochemicals, Inc.,Capaute Chemical, or Tyzor™ products from Dupont Inc., Dynasylan®silanes and organofunctional silanes from Evonik Degussa GmbH Germany,Dow Corning® “Z” silanes or Xiameter® “OFS” silanes from Dow CorningCorp.

Treating agents and treating methods are known in the art, see forexample, U.S. Pat. No. 6,169,142 (col. 4, line 42 to col. 5, line 2).The TMM may comprise at least about 0.05% of a treating agent. The TMMmay comprise up to about 10%, alternatively up to about 5%,alternatively up to about 0.5%, of a treating agent. The treating agentcan be an alkoxysilane having the formula: R⁵ _(x)Si(OR⁶)_((4-x)), wherex is 1, 2, or 3; alternatively x is 3. R⁵ is a substituted orunsubstituted monovalent hydrocarbon group of at least about 1 carbonatom, alternatively at least about 8 carbon atoms. R⁵ has up to about 50carbon atoms, alternatively up to about 30 carbon atoms, alternativelyup to about 18 carbon atoms. R⁵ is exemplified by alkyl groups such ashexyl, octyl, dodecyl, tetradecyl, hexadecyl, and octadecyl; andaromatic groups such as benzyl and phenylethyl. R⁵ can be saturated orunsaturated, branched or unbranched, and unsubstituted. R⁵ can besaturated, unbranched, and unsubstituted.

R⁶ is an unsubstituted, saturated hydrocarbon group of at least about 1carbon atom. R⁶ may have up to about 4 carbon atoms, alternatively up toabout 2 carbon atoms. The treating agent is exemplified byhexyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane,dodecyltrimethyoxysilane, tetradecyltrimethoxysilane,phenylethyltrimethoxysilane, octadecyltrimethoxysilane,octadecyltriethoxysilane, a combination thereof, and others.

Alkoxy-functional oligosiloxanes can also be used as treatment agents.Alkoxy-functional oligosiloxanes and methods for their preparation areknown in the art, see for example, EP 1,101,167 A2. For example,suitable alkoxy-functional oligosiloxanes include those of the formula(R⁶O)_(a)Si(OSiR⁷ ₂R⁸)_(4-a). In this formula, a is 1, 2 or 3,alternatively a is 3. Each R⁶ can be an alkyl group. Each R⁷ is can beindependently selected from unsaturated monovalent hydrocarbon groups ofabout 1 to about 10 carbon atoms. Each R⁸ can be an unsaturatedmonovalent hydrocarbon group having at least about 11 carbon atoms.

Treatment agents for alumina or passivated aluminum nitride couldinclude alkoxysilyl functional alkylmethyl polysiloxanes (e.g., partialhydrolysis condensate of R⁹ _(b)R¹⁰ _(c)Si(O¹¹)_((4-b-c)) orcohydrolysis condensates or mixtures), similar materials where thehydrolyzable group would be silazane, acyloxy or oximo. In all of these,a group tethered to Si, such as R⁹ in the formula above, is a long chainunsaturated monovalent hydrocarbon or monovalent aromatic-functionalhydrocarbon. R¹⁰ is a monovalent hydrocarbon group, and R¹¹ is amonovalent hydrocarbon group of about 1 to about 4 carbon atoms. In theformula above, b is 1, 2, or 3 and c is 0, 1, or 2, with the provisothat b+c is 1, 2, or 3. One skilled in the art could optimize a specifictreatment to aid dispersion of the filler without undue experimentation.

Other specific examples of treating agents such as organo-functionalsilanes have the following typical molecular structure:X—CH₂CH₂CH₂Si(OR)_(3-n)R′_(n) where n=0, 1, 2. Many combinations arepossible, but these are characterized by the fact that they contain twodifferent types of reactive groups. The OR groups are hydrolyzablegroups such as methoxy, ethoxy or acetoxy groups. The group X is anorgano-functional group, such as epoxy, amino, methacryloxy (shownbelow), or sulfido. The presence of some Si-alkyl groups ensures lowsurface tension and good wetting properties. A typical example forsulfido-silanes: (OR)₃Si—(CH₂)₃—S_(x)—(CH₂)₃Si(OR)₃ where x=2 to 8

Use of Fire Retardant or Fire Resistant Additives

In order to reduce the likelihood of fire spreading from anelectrochemical cell to the components of a device it is powering, or toprevent fire spreading within an electrochemical pack, or to prevent anexternal fire from igniting an electrochemical pack, a fire retardant orfire resistant additive can be added to prevent combustion. Materialssuch as Magnesium hydroxide, Al hydroxide, expanded graphite, ammoniumpolyphosphate, phosphate salts, polyphosphate salts, wherein thepolyphosphate can be any mol. wt. or degree of polymerization,pentaerythritol, treated montmorillonite, halogenated compounds,ammonium bromide, chlorinated or brominated molecules, alkanes andpolymers, antimony oxide, antimony trioxide, red phosphorous, magnesiacements, magnesium oxysulphate, magnesium phosphate, magnesium sulphate,boron compounds, borates, boric acid, silicon and silica compounds,melamine and melamine compounds, sol-gels, sodium carbonate, sodiumsilicate, tetrakis(hydroxymethyl)phosphonium salts, halocarbons,including chlorendic acid derivates, halogenated phosphorus compoundsincluding tri-o-cresyl phosphate, tris(2,3-dibromopropyl)phosphate(TRIS), bis(2,3-dibromopropyl)phosphate, tris(1-aziridinyl)-phosphineoxide (TEPA), phosphoramides, triphenyl phosphate (TPP), resorcinoldiphosphate (RDP), bisphenol-a-disphosphate (BPA-DP), organic phosphineoxides, halogenated epoxy resin (tetrabromobisphenol A), etc. includingtheir blends or mixtures.

Additionally, fire retardant additives can include ceramic typetreatments and coatings based on silica, quartz, or other ceramics, asdisclosed in U.S. Pat. No. 6,921,431 to Evans, “Thermal ProtectiveCoating for Ceramic Surfaces,” U.S. Pat. No. 7,105,047, to Simmons,“Thermal Protective Coating,” and non-patent publications byRakotomalala et. al., entitled “Recent Developments in Halogen FreeFlame Retardants for Epoxy Resins for Electrical and ElectronicApplications,” Materials 2010, 3, 4300-4327, the non-patent publicationby the Phosphorous, Inorganic and Nitrogen Flame Retardants Associationentitled “Innovative Flame Retardants in E&E Applications,” June 2009,and the non-patent publication by Feldman, entitled “PolymerNanocomposites: Flammability,” Journal of Macromolecular Science, PartA: Pure and Applied Chemistry, 2013, which are incorporated herein byreference. They can also include ionic materials as disclosed in U.S.patent application Ser. Nos. 12/947,377 and 12/806,267 to Xu, both“Ionic Liquid Flame Retardants,” and which are incorporated herein byreference.

Another example is to have the fire retardant material as part of themicrocapsule shell. For instance, melamine or melamine compounds provideexcellent microcapsule shells and also provide good fire retardantproperties. Sol-gels can also be used as mPCM shells or secondary shellsto give additional fire retardant protection. Any shell material, shellpolymer or secondary shell layer can also incorporate any of the abovefire retardant additives to infer improved fire retardant properties tothe TMM.

Use of Electrically Conducting and Static Charging/Discharging Materialsand Polymers.

In certain embodiments of the disclosure, it may also be advantageous toinclude materials designed to control electrical energy or staticenergy. This electrical energy can either be conducted, discharged,dissipated, stored or other means of moving this energy. As discussedearlier in this disclosure, electrical shorts can damage variouscomponents of a battery cell, and in some circumstances it may bedesirable to keep electrical energy away from the walls of the cell.Metallic materials, such as previously described above, can include anymetal, alloy, oxide, etc. These can also be in any shape or size aspreviously outlined. Many of the previously described thermal conductorscan also be used as electrical conductors. Organic or organic dopedmaterials can also be included in the TMM package. These materials caninclude the general polymer structures shown below:

-   -   Chemical structures of some conductive polymers.    -   From top left clockwise: polyacetylene; polyphenylene vinylene;    -   polypyrrole (X=NH) and polythiophene (X=S);    -   and polyaniline (X=NH/N) and polyphenylene sulfide (X=S)

These and other general classes of conducting polymers can be brokendown as in the below table:

Nitrogen- No heteroatom containing Sulfur-containing Aromatic main chainPoly(fluorene)s Poly(pyrroles)s Poly(thiophene)s (PT) Polyphenylenes(PPY) Poly(3,4- Polypyrenes Poly(o- ethylenedioxythiophene) Polyazulenesaminophenols) (PEDOT) polynaphthalenes (POAP) Poly(p-phenylene sulfide)Polycarbazoles (PPS) Polyindoles Polyazepines Polypyridines Polyanilines(PANI) Double bonds in main Poly(acetylene)s chain (PAC) Aromatic andDouble Poly(p-phenylene Bonds vinylene) (PPV)

More specifically, various materials, polymers and monomers can befurther broken down into more specific charge or radiation conductingmaterials. The various combinations and mixtures of materials usingbelow example materials is infinite and the below examples are notcomplete or inclusive. Infinite combinations can produce variouspolymers, copolymers, mixtures, etc. that can have electricallyconducting and static dissipating properties. These polymers can bedoped with any combination of the infinite number of salts or metallicsalts to enhance the conductivity:

Photosensitizing and charge transport compounds such as1,1,4,4-Tetraphenyl-1,3 butadiene,4-[2-[5-[4-(Diethylamino)phenyl]-4,5-dihydro-1-phenyl-1H-pyrazol-3-yl]ethenyl]-N,N-diethylaniline,5,12-Bis(phenylethynyl)naphthacene, 9,10-Bis(phenylethynyl)anthracene,9,10-Di-p-tolylanthracene, 9,10-Phenanthrenequinone, Benzo[ghi]perylene,Coronene, Julolidine, Pentaphene-78, Perylene-66, Phenanthrene,Phenanthridine, Phenazine, Phenothiazine, Pyrazole-72,Quinacridonequinone, Quinolin-65, Thioxanthone-64, Triphenylene,Violanthrone-79,[4-[Bis(2-hydroxyethyl)amino]phenyl]-1,1,2-ethylenetricarbonitrile

Light Emitters, Dopants, electron & hole transporting materials such as:5,12-Dihydro-5,12-dimethylquino[2,3-b]acridine-7,14-dione,8-Hydroxyquinoline zinc, Anthracene, Benz[b]anthracene, Coumarin 6,Dichlorotris(1,10-phenanthroline)ruthenium(II) hydrate, Lithiumtetra(2-methyl-8-hydroxyquinolinato)boron, Perylene, Platinumoctaethylporphyrin, Rubrene, Tris(2,2′-bipyridyl)dichlororuthenium(II)hexahydrate, Tris(2,2′-bipyridyl-d8)ruthenium(II) hexafluorophosphate,Tris(benzoylacetonato) mono(phenanthroline)europium(III),Tris(dibenzoylmethane) mono(1,10-phenanthroline)europium(111),Tris(dibenzoylmethane) mono(5-amino-1,10-phenanthroline)europium (111),Tris-(8-hydroxyquinoline)aluminum,Tris[1-phenylisoquinoline-C2,N]iridium(III),Tris[2-(4,6-difluorophenyl)pyridinato-C2,N]iridium(III),Tris[2-(benzo[b]thiophen-2-yl)pyridinato-C3,N]iridium(III),Tris[2-phenylpyridinato-C2,N]iridium(III), Metal and salt dopants.

Light Emitting Polymers such as: Cyano-Polyphenylene vinylene (CN-PPV)Polymers including: Poly(2,5-di(hexyloxy)cyanoterephthalylidene),Poly(2,5-di(octyloxy)cyanoterephthalylidene),Poly(2,5-di(3,7-dimethyloctyloxy)cyanoterephthalylidene),Poly(5-(2-ethylhexyloxy)-2-methoxy-cyanoterephthalylidene),Poly(5-(3,7-dimethyloctyloxy)-2-methoxy-cyanoterephthalylidene).

Nitrogen-Containing Polymers including: Poly(2,5 pyridine) and Poly(3,5pyridine).

Poly(fluorenylene ethynylene) (PFE) Polymers including:Poly(9,9-dioctylfluorenyl-2,7-yleneethynylene),Poly[9,9-di(3′,7′-dimethyloctyl)fluoren-2,7-yleneethynylene],Poly[9,9-di(2′-ethylhexyl)fluoren-2,7-yleneethynylene],Poly[9,9-didodecylfluroenyl-2,7-yleneethylnylene].

Poly(phenylene ethynylene) (PPE) Polymers including:Poly(2,5-di(3′,7′-dimethyloctyl)phenylene-1,4-ethynylene),Poly(2,5-dicyclohexylphenylene-1,4-ethynylene),Poly(2,5-di(2′-ethylhexyl)-1,4-ethynylene),Poly(2,5-didodecylphenylene-1,4-ethynylene), andPoly(2,5-dioctylphenylene-1,4-ethynylene).

Polyfluorene (PFO) Polymers and Co-Polymers including:Poly(9,9-di-n-dodecylfluorenyl-2,7-diyl),Poly(9,9-di-n-hexylfluorenyl-2,7-diyl),Poly(9,9-di-n-octylfluorenyl-2,7-diyl),Poly(9,9-n-dihexyl-2,7-fluorene-alt-9-phenyl-3,6-carbazole),Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)],Poly[(9,9-dihexylfluoren-2,7-diyl)-alt-(2,5-dimethyl-1,4-phenylene)],Poly[(9,9-dihexylfluoren-2,7-diyl)-co-(9-ethylcarbazol-2,7-diyl)],Poly[(9,9-dihexylfluoren-2,7-diyl)-co-(anthracen-9,10-diyl)],Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophene],Poly[9,9-bis-(2-ethylhexyl)-9H-fluorene-2,7-diyl].

Polyfluorene-Vinylene (PFV) Co-Polymers including:Poly((9,9-dihexyl-9H-fluorene-2,7-vinylene)-co-(1-methoxy-4-(2-ethylhexyloxy)-2,5-phenylenevinylene)),Poly(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene),Poly(9,9-di-n-hexylfluorenyl-2,7-vinylene),Poly[(9,9-di-(2-ethylhexyl)-9H-fluorene-2,7-vinylene)-co-(1-methoxy-4-(2-ethylhexyloxy)-2,5-phenylenevinylene)],andPoly[9-(2-ethylhexyl)-3,6-carbazolevinylene-alt-2,6-naphthalenevinylene].

Polyphenylene Vinylene (PPV) Polymers and Co-Polymers including:Poly(1-methoxy-4-(3-propyloxy-heptaisobutyl-PSS)-2,5-phenylenevinylene)-co-(1-methoxy-4-(2-ethylhexyloxy)-2,5-phenylenevinylene)(60:40), Poly(1-methoxy-4-(O-disperse Red 1))-2,5-phenylenevinylene,Poly(2,5-bis(1,4,7,10-tetraoxaundecyl)-1,4-phenylenevinylene),Poly(2,5-dihexyloxy-1,4-phenylenevinylene),Poly(2,5-dioctyl-1,4-phenylenevinylene), Poly(2,6-naphthalenevinylene),Poly(p-xylene tetrahydrothiophenium chloride),Poly[(m-phenylenevinylene)-alt-(2,5-dibutoxy-p-phenylenevinylene)],Poly[(m-phenylenevinylene)-alt-(2,5-dihexyloxy-p-phenylenevinylene)],Poly[(m-phenylenevinylene)-alt-(2-methoxy-5-(2-ethylhexyloxy)-p-phenylenevinylene)],Poly[(m-phenylenevinylene)-alt-(2-methoxy-5-octyloxy-p-phenylenevinylene)],Poly[(m-phenylenevinylene)-co-(2,5-dioctoxy-p-phenylenevinylene)],Poly[(o-phenylenevinylene)-alt-(2-methoxy-5-(2-ethylhexyloxy)-p-phenylenevinylene)],Poly[(p-phenylenevinylene)-alt-(2-methoxy-5-(2-ethylhexyloxy)-p-phenylenevinylene)],Poly[1-methoxy-4-(3-propyloxy-heptaisobutyl-PSS)-2,5-phenylenevinylene],Poly[1-methoxy-4-(3-propyloxy-heptaisobutyl-PSS)-2,5-phenylenevinylene]-co-[1-methoxy-4-(2-ethylhexyloxy)-2,5-phenylenevinylene] (30:70),Poly[2,5-bis(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene],Poly[2,5-bisoctyloxy)-1,4-phenylenevinylene],Poly[2-(2′,5′-bis(2″-ethylhexyloxy)phenyl)-1,4-phenylenevinylene],Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene],Poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene],Poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene] potassium salt,Poly[tris(2,5-bis(hexyloxy)-1,4-phenylenevinylene)-alt-(1,3-phenylenevinylene)],andPoly{[2-[2′,5′-bis(2″-ethylhexyloxy)phenyl]-1,4-phenylenevinylene]-co-[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene]}.

Polythiophene Polymers and Co-Polymers (regioregular or regiorandomstearic configurations) including:Poly(3-(2-methoxyethoxy)ethoxymethylthiophene-2,5-diyl),Poly(3,4-ethylenedioxythiophene), Poly(3-butylthiophene-2,5-diyl),Poly(3-cyclohexyl-4-methylthiophene-2,5-diyl),Poly(3-cyclohexylthiophene-2,5-diyl),Poly(3-decyloxythiophene-2,5-diyl), Poly(3-decylthiophene-2,5-diyl),Poly(3-dodecylthiophene-2,5-diyl), Poly(3-hexylthiophene-2,5-diyl),Poly(3-octylthiophene-2,5-diyl),Poly(3-octylthiophene-2,5-diyl-co-3-decyloxythiophene-2,5-diyl),Poly(thiophene-2,5-diyl), bromine terminated,Poly[(2,5-didecyloxy-1,4-phenylene)-alt-(2,5-thienylene)].

Water-Soluble light emitting polymers including:Poly(2,5-bis(3-sulfonatopropoxy)-1,4-phenylene, disodiumsalt-alt-1,4-phenylene), Poly[(2,5-bis(2-(N,N-diethylammoniumbromide)ethoxy)-1,4-phenylene)-alt-1,4-phenylene],Poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene] potassium salt,Poly{[2,5-bis(2-(N,N-diethylamino)ethoxy)-1,4-phenylene]-alt-1,4-phenylene}

Polymer Hole Transport and Host Materials including Polyvinyl polymerssuch as: Poly(1-vinylnaphthalene), Poly(2-vinylcarbazole),Poly(2-vinylnaphthalene), Poly(9-vinylcarbazole), andPoly(N-ethyl-2-vinylcarbazole).

Conducting polymers, copolymers and monomers including Polyacetylenessuch as Poly[1,2-bis(ethylthio)acetylene], Poly(phenylene sulfides),Polyanilines, copolymers and Polyaniline Dopants includingCamphor-10-sulfonic acid (β), Dinonylnaphthalenesulfonic acid,Dodecylbenzenesulfonic acid, Polyaniline (emeraldine base, emeraldinesalt, leucoemeraldine base, nigraniline, or pernigraniline),o-ethoxyaniline, ortho & meta mono- and di-substituted anilines, orthoor meta-aminoacetophenone, and m-toluidine.

Polypyrroles and Pyrrole Monomers including: 1H-Pyrrole-1-propanoicacid, 3,4-Ethylenedioxypyrrole-2,5-dicarboxylic acid,3,4-Ethylenedioxypyrrole, 3,4-Propylenedioxypyrrole,4-(3-Pyrrolyl)butyric acid, Diethyl1-benzyl-3,4-ethylenedioxypyrrole-2,5-dicarboxylate, and Polypyrrole(conductive, doped or undoped).

Polythiophenes and Thiophene Monomers including:3,4-Ethylenedioxythiophene, Poly(3,4-ethylenedioxythiophene),bis-poly(ethyleneglycol), lauryl terminated,Poly(3,4-ethylenedioxythiophene), tetramethacrylate end-capped,Poly(3,4-ethylenedioxythiophene)-block-poly(ethylene glycol),Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate),Poly(3,4-ethylenedioxythiophene),Poly(thiophene-3-[2-(2-methoxyethoxy)ethoxy]-2,5-diyl).

Sulfonated versions of Polyfluorenes, Poly(o-aminophenols) (POAP),Polytetrathiafulvalenes, Polynapththalenes, Poly (para-phenylenevinylene)s, natural or Biological Melanin pigment polymers.

Organic Photovoltaic materials including: Conducting Materials such as5,5′″″-Dihexyl-2,2′:5′,2″:5″,2′″:5′″,2″″:5″″,2′″″-sexithiophene,Copper(II)1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine,Copper(II) phthalocyanine, Fullerene-C₆₀, Fullerene-C₈₄, Pentacene,Perylene-3,4,9,10-tetracarboxylic dianhydride, Perylene,Poly(3-dodecylthiophene-2,5-diyl), Poly(3-hexylthiophene-2,5-diyl)regioregular, Poly(3-octylthiophene-2,5-diyl) regioregular,Poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene],Tris[4-(5-dicyanomethylidenemethyl-2-thienyl)phenyl]amine,[5,6]-Fullerene-C₇₀, [6,6]-Pentadeuterophenyl C₆₁ butyric acid methylester, [6,6]-Phenyl C₆₁ butyric acid methyl ester, [6,6]-Phenyl C₇₁butyric acid methyl ester, [6,6]-Phenyl C₈₅ butyric acid methyl ester,[6,6]-Thienyl C₆₁ butyric acid methyl ester, [6.6] Diphenyl C₆₂bis(butyric acid methyl ester), and α-Sexithiophene.

Dyes including1,3-Bis[4-(dimethylamino)phenyl]-2,4-dihydroxycyclobutenediyliumdihydroxide, bis(inner salt), 7-Methylbenzo[a]pyrene,9,10-Dihydrobenzo[a]pyrene-7(8H)-one, Benzo[e]pyrene, Coumarin 102,Coumarin 153, Coumarin 30, Coumarin 480 D, Coumarin 6, Merocyanine 540and Pyrene.

Particles and their doped, undoped, various crystal forms, and mixtureswith metals including: Titanium oxide, Titanium dioxide, Titanium⁺⁴oxides and dioxides, and Zinc oxide.

Organic Semi-conductors including n-Type Oligomers and Polymers such as1,4,5,8-Naphthalenetetracarboxylic dianhydride,2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane,5,10,15,20-Tetrakis(pentafluorophenyl)-21H,23H-porphine palladium(II),7,7,8,8-Tetracyanoquinodimethane, Copper(II)1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine,Fullerene-C₆₀, Fullerene-C₈₄,N,N′-Dioctyl-3,4,9,10-perylenedicarboximide,N,N′-Dipentyl-3,4,9,10-perylenedicarboximide,N,N′-Diphenyl-3,4,9,10-perylenedicarboximide,N,N′-Bis(2,5-di-tert-butylphenyl)-3,4,9,10-perylenedicarboximide,Perylene-3,4,9,10-tetracarboxylic dianhydride, [5,6]-Fullerene-C₇₀,[6,6]-Phenyl C₆₁ butyric acid methyl ester, [6,6]-Phenyl C₇₁ butyricacid methyl ester, [6,6]-Phenyl C₈₅ butyric acid methyl ester,[6,6]-Phenyl-C₆₁ butyric acid butyl ester, [6,6]-Phenyl-C₆₁ butyric acidoctyl ester, [6,6]-Thienyl C₆₁ butyric acid methyl ester, [6,6] DiphenylC₆₂ bis(butyric acid methyl ester),Poly(2,5-di(hexyloxy)cyanoterephthalylidene),Poly(2,5-di(octyloxy)cyanoterephthalylidene),Poly(2,5-di(3,7-dimethyloctyloxy)cyanoterephthalylidene),Poly(5-(2-ethylhexyloxy)-2-methoxy-cyanoterephthalylidene),Poly(5-(3,7-dimethyloctyloxy)-2-methoxy-cyanoterephthalylidene),Poly(benzimidazobenzophenanthroline),Poly[(1,4-divinylenephenylene)(2,4,6-triisopropylphenylborane)], andPoly[(2,5-didecyloxy-1,4-phenylene) (2,4,6-triisopropylphenylborane)],diphenyl terminated.

p-Type Oligomers and Polymers including:13,6-N-Sulfinylacetamidopentacene, 2,2′:5′,2″:5″,2′-Quaterthiophene,3,3′″-Didodecyl-2,2′:5′,2″:5″,2′″-quaterthiophene,3,3′″-Dihexyl-2,2′:5′,2″:5″,2′″-quaterthiophene,5,5′″″-Dihexyl-2,2′:5′,2″:5″,2′″:5′″,2″″:5″″,2′″″-sexithiophene,5,5′-Di(4-biphenylyl)-2,2′-bithiophene, 5,5′-Dihexyl-2,2′-bithiophene,6,13-Dihydro-6,13-methanopentacene-15-one, Benz[b]anthracene,Benz[b]anthracene, Bis(ethylenedithio)tetrathiafulvalene, Copper(II)phthalocyanine, Coronene purified by sublimation,Dibenzotetrathiafulvalene, Pentacene,Pentacene-N-sulfinyl-n-butylcarbamate adduct,Pentacene-N-sulfinyl-tert-butylcarbamate, Platinum octaethylporphyrin,Rubrene, Tetrathiafulvalene,Tris[4-(5-dicyanomethylidenemethyl-2-thienyl)phenyl]amine,a-Sexithiophene, Poly(3-dodecylthiophene-2,5-diyl) regiorandom orregioregular, Poly(3-hexylthiophene-2,5-diyl) regiorandom orregioregular, Poly(3-octylthiophene-2,5-diyl) regiorandom orregioregular,Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)],Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophene],Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene],Poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene]

Use of Other Additives

Suitable antioxidants are known in the art and are commerciallyavailable. Suitable antioxidants include phenolic antioxidants andcombinations of phenolic antioxidants with stabilizers. Phenolicantioxidants include fully sterically hindered phenols and partiallyhindered phenols. Stabilizers include organophosphorous derivatives suchas trivalent organophosphorous compound, phosphites, phosphonates, and acombination thereof; thiosynergists such as organosulfur compoundsincluding sulfides, dialkyldithiocarbamate, dithiodipropionates, and acombination thereof; and sterically hindered amines such astetramethyl-piperidine derivatives. Suitable antioxidants andstabilizers are disclosed in Zweifel, Hans, “Effect of Stabilization ofPolypropylene During Processing and Its Influence on Long-Term Behaviorunder Thermal Stress,” Polymer Durability, Ciba-Geigy AG, AdditivesDivision, CH-4002, Basel, Switzerland, American Chemical Society, vol.25, pp. 375-396, 1996. Suitable antioxidants are supplied by BASF Corp.under the Irgafos® and Irganox® tradenames. Antioxidants supplied byChemtura Corp. under the Naugalube® and Naugard® tradenames. Stabilizersand antioxidants supplied by Nanjing Union Rubber and Chemicals Co.,Ltd.

Suitable phenolic antioxidants include vitamin E, IRGANOX B225 andIRGANOX 1010 from BASF Corp., IRGANOX 1010 comprises pentaerythrioltetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate).

Reaction catalyst inhibitors are known in the art and commerciallyavailable, see for example, U.S. Pat. No. 5,929,164 (col. 1, line 65 tocol. 3, line 65). Inhibitors can be a phosphine, a diphosphine, anamine, a diamine, a triamine, an organic sulfide, an alkenyl-functionalcompound, an alkynyl-functional compound, a hydroxy-functional compound,a combination thereof, or any other transition metal catalyst poison.

Suitable phosphines include trialkyl phosphines and triaryl phosphinessuch as triphenyl phosphine. Suitable diphosphines includetetraphenylethylene diphosphine. Suitable amines include n-butyl amineand triethanolamine. Suitable diamines include tetramethylenediamine.Suitable organic sulfides include ethyl phenyl sulfide. Suitablealkenyl-functional compounds can be organic, organosilicones, ororganosilanes. Suitable alkenyl-functional compounds includevinylsiloxanes and vinylsilanes. Suitable alkynyl functional compoundscan be organic, such as acetylene, propyne, 1-butyne, 1-pentyne,4,4-dimethyl-1-pentyne, 1-hexyne, 5-methyl-1-hexyne, and 1-decyne.

Methods of Manufacture of the PCM and TMM—Structure for TemperatureManagement and Heat Dissipation

The TMM can be prepared by any convenient means such as mixing allcomponents together at higher temperatures. In many embodiments, thistemperature is higher than the phase change temperature of thePCM/pPCM/fpPCM. The TMM can be manufactured by addition of ingredientsin a certain order to facilitate specific reactions or interactions suchas the pretreatment of the fillers and particles with coupling agents orsilanes. The TMM can be mixed at low, room temperature or highertemperatures. The TMM can be prepared in mixing vessels, reactors,extruders or the like.

The embodiments can be manufactured by a variety of known methods suchas flow molding, reaction molding, reaction injection molding, vacuummolding, etc. The composite can be prepared by batch mixing of theingredients, degassing, and pouring or injecting into the mold. Theformulations can also be mixed using 2 component equipment where theingredients are stored separately, then metered, into a mixing chamberor static mixing tube, then pumped or filled into molds. The mold cantake the article, casing or battery block final shape, or the mold canbe a generic shape then machined and formed into the final shape.

Formulation and Manufacturing of Films, Tapes, and Coatings of PCM-TMMs

As discussed previously with reference to FIG. 5A, in some embodimentsof the disclosure, PCM-TMM may be shaped into a tube, sleeve, or similarcasing. The tube, sleeve, or similar casing may be manufactured using avariety of methods, including injection molding, profile molding, tubemolding, or hose molding. During the molding process, the PCM-TMM may bein a liquid state

As discussed previously with reference to FIG. 5B, in some embodimentsof the disclosure, a PCM-TMM may be formulated into a film or tape thatcan be wrapped around a battery cell to achieve a desired thickness oramount. In general, this film or tape can be made by casting or coatinga substrate, or by skiving a larger amount of material. During thecasting or coating process, the PCM-TMM (e.g., an elastomeric TMMcontaining one or more pPCMs) may be in a liquid state.

An alternative method of making film, tape or sheet is to form a billet,plug, cylinder, ingot, shaft, tube, wheel, cartridge, or bobbin of thePCM-TMM material and skive the material into film or sheet of variousthicknesses. The skiving process entails continuously slicing thinlayers of the PCM-TMM off the cylinder to form a sheet or film.

A substrate upon which a PCM-TMM may be cast or coated can be adhesiveand/or conductive. Conductive substrates can be heat spreaders such as ametallic foil (e.g., copper, aluminum, gold, silver, etc.) or a carbonfoil (e.g., graphite, graphene, diamond, etc.). These substrates couldalso comprise reflective insulation layers, such as for protecting fromextreme cold. Any of the foils mentioned herein could have a separateadhesive backing made of either conductive or non-conductive adhesives.Alternatively, an adhesive itself could be the substrate of the PCM-TMM.

In certain embodiments of the disclosure, the formulation of the PCM-TMMused to coat the substrate to make the film or tape may haveparticularly high particulate loading with particulate loadings up toabout 80% of PCM microcapsules and/or conductivity additives. Suchconductivity additives will be described presently. Because of the highparticulate loading, the coating formulations may be very thick andviscous, such that solvent is needed for application. It is verydifficult to coat thick films, then dry and cure them by driving thesolvent from the film, because the film that is applied may become toothick and trap the solvents. This trapping creates problems when tryingto drive the solvent from the film, such as foaming, bubbling, anduneven surfaces.

One way to correct the problems created by using a solvent is to use apolymerizable or reactable molecule or monomer as the solvent. It wouldbe desirable if this polymerizable monomer that is used as a solventalso can then polymerize into a polymeric PCM itself. One example ofsuch a solvent is octadecyl methacrylate monomer. It can be combinedwith a TMM mixture containing microencapsulated or other contained PCMsto create a low viscosity coating. This coating can be casted or appliedto a substrate, and when it is cured, the octadecyl methacrylate monomerwill form a polyoctadecyl methacrylate (which has a melting point of˜30° C. and a latent heat of ˜81 J/g) polymeric PCM which also containsother contained PCMs, (i.e. microencapsulated PCMs, silica absorbed PCM,etc.). Any such monomers, oligomers, and other chemicals discussedthroughout this disclosure that also have the capability of being usedas a solvent and then polymerizing into a polymeric PCM may be similarlyutilized in this coating process.

The various film and tape embodiments discussed herein, as well asvarious sleeve embodiments, may be cured through known processes of UVand radiation curing. Such processes of UV and radiation coating aredisclosed in the book “UV Coatings: Basics, Recent Developments, and NewApplications,” by Reinhold Schwalm, Elsevier, 2007, which isincorporated herein by reference. Such processes and techniques are alsodisclosed in the technical bulletin “Ultraviolet and Electron (UV/EB)Cured Coatings, Inks, and Adhesives,” published by the United StatesEnvironmental Protection Agency, July 2001, which is incorporated hereinby reference. For further disclosure of compositions and methods ofmanufacture for films according to embodiments of this disclosure, referto the commonly owned and co-pending application entitled “ThermalManagement Films Containing Phase Change Materials,” U.S. applicationSer. No. ______, filed on ______ previously incorporated by reference.

Additional Application Forms

The fpPCM, pPCM, mPCM, PCM, additives and finished TMM can beimplemented as a tube, sleeve, casing, coating, laminate, infusion,treatment, gums, gels, film, sheets, greases, waxes or ingredient in acoating, laminate, infusion, treatment, caulks, gums, gels, film,sheets, tapes, greases, waxes that is formed adjacent to, on or withinelectrochemical cells or electrochemical cell components and materialsusing any suitable coating, laminating, layering, infusion, etc.technique. Application techniques and forms can include manually ormechanically sliding a tube, sleeve, or casing around a battery cell,using gels, greases or wax to assist the manual or mechanicalapplication, manually or mechanically wrapping a film or tape one ormore times, spray coating, air atomized spraying, airless atomizedspraying, electrostatic spraying, slot die coating, contact slotcoating, curtain coating, knife coating, roller coating, kiss coating,transfer coating, foam coating, brushing, screenprinting, padding,dipping or immersion, saturating, printing, pressure or gravity feednozzles/guns, hot melt applicators, pump guns, manually operated guns,syringes, needle guns, various shape and size nozzles, molding,overmolding, injection molding, RIM, prepeg, Resin infusion process suchas resin transfer molding (RTM), vacuum infusion process (VIP) andvacuum assisted RTM (VARTM), pultrusion, extrusion, plasma, etc. The TMMcan be applied to release sheets or other temporary substrate surfacefor packaging/shipment then subsequently transferred to the batteries orbattery packs, i.e. indirect transfer processes. The TMM may bemanufactured as individual electrochemical-cell-sized tubes or sleevesfor packaging/shipment and subsequent transfer by an end user. The TMMmay also be manufactured in sheets of tape or film as described hereinfor wrapping around individual cells. Such sheets of tape or film may bemanufactured in standard sizes that anticipate the number of times thesheet may be wrapped around an individual electrochemical cell, and thestandard sizes and shapes can vary depending on anticipatedapplications.

The TMM can also be constructed as a unitary case with individualreceptacles for individual electrochemical cells, such as those depictedin FIG. 4C. For example, certain electrochemical packs that housemultiple cells, such as those for automobiles or airplanes, may beconstructed such that the TMM comprises a honeycomb-like structure thatfits a predetermined number of cells. The unitary cases can be formedsuch that multiple receptacles for individual electrochemical cells forma line, a square, a cube, a rectangle, a circle, stacks, or any othershape. Cases can comprise modular subunits of more than one, but lessthan all of the sleeves necessary for a particular battery pack. Forexample, an electrochemical pack comprising 32 cells may have foursubunit rows of eight sleeves that are constructed unitarily.

The application process can be run cold, warm, hot or at roomtemperature, i.e. above or below room temperature, i.e. −100° C. to 400°C. Curing, crosslinking, drying or further reactions of the TMM orvarious layers to either cause bonding between or within the layers, orto facilitate the application of additional layers can be accomplishedby any energy source. Examples are thermal, heat, light, UV, IR,radiation, solar, induction, pressure, sonic or sound waves, x-ray,radio waves, gamma waves, microwave, laser, e-beam, plasma, etc.

During use or application, the PCM-TMM can be positioned so that it isadjacent to an area in between an electrochemical cell or pack and adevice that the cell or pack is powering, such that the cell or pack isprotected from its own heat and the device components themselves areprotected from the electrochemical device's heat. Additionally, thePCM-TMM may be positioned in between two or more electrochemical cellsthat each produce their own heat. It is also contemplated that thePCM-TMM can be positioned so that it is exposed to an outsideenvironment, thus serving to facilitate temperature to the outside,protect internal cells packs from the outside environment or protectusers from electrochemical device overheating.

The PCM-TMM may have a uniform thickness around the outside of any givenindividual electrochemical cell, or it may have varying degrees ofthickness depending upon where the PCM-TMM is located in relation to anindividual cell. For example, the PCM-TMM may be thicker in between twobatteries of a battery pack than on the outside of one of the batteriesof a battery pack, because the PCM-TMM in between two batteries mustmanage the temperature of two batteries instead of one. Alternatively,the PCM-TMM on the outside of a battery pack may be thicker than on theinside because the particular battery pack may be in an environmentwhere the outside temperature is higher than that created by the cellsor battery packs themselves. In some embodiments, the PCM-TMM may notcover the entire surface area of a cell. For example, one or both of theterminals of a battery may need to be exposed in order to contact theterminals on the device it powers or the terminals of other batteries ina pack. Additionally, in some embodiments, the PCM-TMM may be applied ina non-uniform thickness around a particular cell. For example, forcertain applications, it may be desirable to apply the PCM-TMM moredensely around a section of a cell that produces more heat than anothersection of the cell. The variety in thickness may allow for a moreadvantageous use of space.

In some embodiments, multiple layers of PCM-TMMs with differentcompositions are utilized. It is contemplated that any PCM-TMM article,such as a tube, sleeve, or wrapped tape, can include as few or as manylayers as required for various implementations. In particular, it iscontemplated that other layers of PCM-TMM can cover cells or packs indifferent orientations to main layers of PCM-TMM. For example, a batterypack constructed in a unitary fashion to receive individual cylindricalbattery cells may have openings on the top and bottom to expose batteryterminals, but additional PCM-TMM material may be added across thebottom or top to cover more of the surface area of the terminals oncethe batteries are inserted. For example, a battery pack may comprisemultiple batteries that are each inserted into sleeves. Then each of thecells' terminals may be connected to each other, to the deviceterminals, or to a protection circuit. A layer of additional PCM-TMM maybe applied after such connections are constructed. Such a layer can beimplemented in a similar fashion as the first sleeve of PCM-TMM or canbe implemented in another fashion to provide different functionality,such as shape-fitting, water repellency, stain resistance, stiffness,impact resistance, etc. The PCM-TMM can be applied to provide acontinuous coating, encapsulant or complete coverage, or the PCM-TMM canbe used in a discontinuous pattern.

It should be clearly understood that by providing examples of specificcompositions, applicant does not intend to limit the scope of the claimsto any of these specific composition. To the contrary, it is anticipatedthat any combination of the functional groups, polymeric phase changematerials, and articles described herein may be utilized to achieve thenovel aspects of the present disclosure. The claims are not intended tobe limited to any of the specific compounds described in thisdisclosure, any disclosure incorporated herein or the example givenabove.

While the present disclosure has been described with reference to thespecific embodiments thereof, it should be understood by those skilledin the art that various changes may be made and equivalents may besubstituted without departing from the true spirit and scope of thedisclosure as defined by the appended claims. In addition, manymodifications may be made to adapt a particular situation, material,composition of matter, method, process step or steps, to the objective,spirit and scope of the present disclosure. All such modifications areintended to be within the scope of the claims appended hereto. Inparticular, while the methods disclosed herein have been described withreference to particular steps performed in a particular order, it willbe understood that these steps may be combined, sub-divided, orre-ordered to form an equivalent method without departing from theteachings of the present disclosure. Accordingly, unless specificallyindicated herein, the order and grouping of the steps is not alimitation of the present disclosure.

What is claimed is:
 1. A casing for the thermal management andprotection of an electrochemical cell, the casing comprising: a firstmaterial; an inner surface configured to be in physical contact with atleast a portion of an outer surface of an electrochemical cell, whereinthe inner surface is substantially solid at room temperature; a polymermatrix dispersed within the first material and comprising two or moretemperature management materials, at least one of the two or moretemperature management materials comprising, a phase change materialhaving a latent heat of at least 5 Joules per gram and a transitiontemperature between 0° C. and 100° C., and at least one other of the twoor more temperature management materials comprising, an elastomericmaterial, wherein the polymer matrix is substantially homogeneous, andwherein, in an environment where the electrochemical cell and a secondelectrochemical cell operate under the same charging and dischargingconditions, the casing reduces a first operating temperature of theelectrochemical cell by at least 10° C. compared to a second operatingtemperature of the second electrochemical cell encased by a secondcasing comprising the first material and not the polymer matrix.
 2. Thecasing of claim 1, wherein the phase change material is a polymericphase change material.
 3. The casing of claim 2, wherein the phasechange material is a functional polymeric phase change material.
 4. Thecasing of claim 1, further comprising; a second polymer matrixcomprising one or more temperature management materials, wherein thesecond polymer matrix forms a layer upon on the polymer matrixcomprising two or more temperature management materials.
 5. The casingof claim 1, wherein the casing comprises a cylindrical sleeve.
 6. Thecasing of claim 1, wherein the casing comprises a film.
 7. The casing ofclaim 1, wherein the casing has a Shore A hardness of greater than 85and a Shore D hardness of greater than 25 (per ASTM D2240).
 8. Thecasing of claim 1, wherein the casing has a flex modulus of greater than15 pounds per square inch and a break elongation of greater than 20%. 9.The casing of claim 1, further comprising a gel disposed upon at least aportion the casing.
 10. The casing of claim 1, wherein the polymermatrix is cross-linked with an average of between 0.05 to 1.0 crosslinksper polymeric chain.
 11. The casing of claim 1, wherein the phase changematerial has a latent heat content of greater than 10 Joules per gramand less than 60 Joules per gram.
 12. The casing of claim 1, wherein thecasing is further comprised of one or more additives selected from thegroup comprising: a fire-retardant additive, an energy conductivityadditive, a thermal conductivity additive, a waterproofing additive, anucleating agent, and an antioxidant.
 13. The casing of claim 1, whereinthe casing further comprises a reflective insulating layer.
 14. Acontainer for the thermal management and protection of anelectrochemical cell pack configured to be in physical contact with aplurality of electrochemical cells, wherein; the container issubstantially solid at room temperature and comprises: a first material;a polymer matrix comprising two or more temperature managementmaterials, at least one of the two or more temperature managementmaterials comprising; a phase change material having a latent heat of atleast 5 Joules per gram and a transition temperature between 0° C. and100° C., and at least one other of the two or more temperaturemanagement materials comprising; an elastomeric material; wherein thepolymer matrix is substantially homogeneous, and wherein, in anenvironment where the electrochemical cell pack and a secondelectrochemical cell pack operate under the same charging anddischarging conditions, the container reduces a first operatingtemperature of at least one electrochemical cell in the electrochemicalcell pack by at least 10° C. compared to a second operating temperatureof at least one electrochemical cell of the second electrochemical cellpack encased by a second container comprising the first material and notthe polymer matrix.
 15. The container of claim 14, wherein the containercomprises a plurality of interconnected sleeves.
 16. The container ofclaim 14, wherein the phase change material is microencapsulated. 17.The container of claim 14, wherein the phase change material is apolymeric phase change material.
 18. The container of claim 17, whereinthe polymeric phase change material is a functional polymeric phasechange material.
 19. The container of claim 14, further comprising a geldisposed on at least a portion of the container.
 20. The container ofclaim 14, wherein the container comprises a film.
 21. The container ofclaim 14, further comprising one or more additives selected from thegroup comprising: a fire-retardant additive, an energy conductivityadditive, a thermal conductivity additive, a waterproofing additive, anucleating agent, and an antioxidant.
 22. The casing of claim 1, whereinthe phase change material comprises: a composite polymeric phase changematerial comprising a polyether polyol and one or more branching orcrosslinking agents, wherein when the branching agent or crosslinkingagent is reacted with the polyether polyol in a ratio of betweenapproximately 0.5:1 and 1.5:1, and the branching agent or crosslinkingagent changes a length of a chain of the polyether polyol.
 23. Thecasing of claim 22, wherein the polyether polyol comprises polyethyleneglycol.
 24. The casing of claim 22, wherein the crosslinking agent orchain extending agent comprises a branched crosslinking agent or chainextending agent.
 25. The casing of claim 1, wherein the casing ismachinable.
 26. The casing of claim 1, wherein the casing is moldable.27. The casing of claim 1, wherein the phase change material is asolid-solid phase change material.